CBSE Class 10

In this page, we are providing Management of Natural Resources Class 10 Extra Questions and Answers Science Chapter 16 pdf download. NCERT Extra Questions for Class 10 Science Chapter 16 Management of Natural Resources with Answers will help to score more marks in your CBSE Board Exams.

Class 10 Science Chapter 16 Extra Questions and Answers Management of Natural Resources

Extra Questions for Class 10 Science Chapter 16 Management of Natural Resources with Answers Solutions

Extra Questions for Class 10 Science Chapter 16 Very Short Answer Type

Question 1.
List any two causes for deforestation taking place.  (CBSE 2009)
Answer:

1. Meeting the needs of growing population and using land for housing.
2. Setting up industries.
3. Converting into agricultural land.

Question 2.
Name any two forest products each of which is the basis for some industry. (CBSE 2009)
Answer:

1. Timber wood: Used in making paper and furniture.
2. Latex of rubber plant: In making tyres.
3. Resins and gums: Used in paints and varnishes.

Question 3.
Mention any one negative effect of our affluent life style on the environment.  (CBSE 2013, 2014)
Answer:
Chlorofluorocarbons used in refrigerators causing ozone hole. Carbon dioxide released on burning fossil fuels causing global warming.

Question 4.
List any two measures that you suggest for better management of water resources.  (CBSE 2013, 2014)
Answer:

1. Rainwater harvesting.
2. Reusing the rinsed water from washed clothes for cleaning or mopping the house.

Question 5.
Give one example each from your daily life where the household waste can be effectively reused and recycled respectively.  (CBSE 2013, 2014)
Answer:
Reuse: Empty plastic or glass bottles of jams and pickles
Recycle: Paper and empty polypacks of milk.

Question 6.
Name any two items which can be easily recycled but are generally thrown in the dustbins by us.  (CBSE 2013, 2014)
Answer:
Paper, polypacks of milk, cold drink cans, etc.

Question 7.
Write the main objective of conservation of biodiversity.  (CBSE 2013)
Answer:
To maintain ecological balance as loss of biodiversity leads to ecological instability.

Question 8.
Water is a valuable resource. List two ways that you would suggest every family member to save this resource. (CBSE 2014)
Answer:

1. Prevent leakage from tap and ensure timely repairs.
2. Reuse the rinsed water from washed clothes for watering plants in garden.

Question 9.
“We need to manage our resources”. List two reasons to justify this statement.  (CBSE 2014)
Answer:

1. For equitable distribution of resources so that all people get their benefits.
2. Many resources are limited and would exhaust due to overexploitation.

Extra Questions for Class 10 Science Chapter 16 Short Answer Type I

Question 1.
List any four measures for conserving forests.  (CBSE 2009)
Answer:

1. Reduce the indiscriminate felling of trees.
2. Create awareness among people for conservation of forests.
3. Involving local people in management and conservation of forests.
4. Reforestation by promoting silviculture.
5. Providing protection to wildlife and endangered plants.
6. Making strict laws for conservation of forests.

Question 2.
List any four advantages of water harvesting.  (CBSE 2009)
Answer:

1. Helps to recharge ground water.
2. Underground water does not act as breeding ground of mosquitoes.
3. Underground water does not get contaminated by human and animal wastes.
4. Provides moisture to the soil and crops.

Question 3.
We often observe domestic waste decomposing in the by lanes of residential colonies. Suggest ways to make people realise that the improper disposal of waste is harmful to the environment.  (CBSE 2013)
Answer:

• Create awareness through campaigns and road rallies on the issue.
• Impose penalty on those found throwing wastes on the road.

Question 4.
List two environment-friendly practices or habits which need to be followed by every member of a family / community. Explain how these practices will support the “save the environment” mission. (CBSE 2014)
Answer:

• Segregation of wastes into biodegradable and non-biodegradable and ensuring their reuse and recycling, if possible.
• Less use of fossil fuels and switching to environment friendly alternatives like use of solar energy and wind energy, etc.

Question 5.
What is meant by “Sustainable Management”? Why is reuse considered better than recycling?  (CBSE 2015)
Answer:
The judicious and wise use of resources to cater to the current basic needs and preserving the resources for the needs of future generations is called as Sustainable Management.
Recycling requires more amount of energy and money while no energy is required for the reuse of materials. So, reuse is better than recycling.

Question 6.
List two advantages associated with water harvesting at the community level. (CBSE 2015)
Answer:
Water harvesting at community level is advantageous as:

• It recharges the ground water and helps in increasing the vegetation around the area.
• It mitigates the chances of droughts and floods. It also increases income of farmers by increasing agricultural production in rural areas.

Question 7.
Everyone of us can do something to reduce our personal consumption of various natural resources. List four such activities based on 3R’s approach.  (CBSE 2013, 2015)
Answer:

• Reduce wastage of water by repairing leaking taps.
• Recycle the wastes like paper, empty polypacks of milk, etc.
• Reuse the aluminium cans of cold drink, glass bottles of pickles, etc.
• Reduce the use of fossil fuels by switching over to cleaner and renewable sources of energy like solar energy.

Question 8.
List two main causes of the pollution of water of the river Ganga. State how pollution and
contamination of river water prove harmful for the health of the people of neighbouring areas. (CBSE 2015)
Answer:
The two main causes of pollution of water of river Ganga are:

1. Disposal of domestic and industrial effluents into it.
2. Human activities like washing clothes, bathing, etc.

The harm to the people of neighbouring areas are:

1. Leads to water-borne diseases like cholera, typhoid, etc.
2. Harms the aquatic plants and animals in the water body.

Question 9.
List any two advantages associated with water stored in the ground.  (CBSE 2015)
Answer:
The water stored in ground

1. does not evaporate
2. does not act as breeding ground of mosquitoes.

Question 10.
What steps have been taken by West Bangal Government to protect badly degraded sal forests?
Answer:
By the efforts of A.K . Banerjee in Arabari forest range of Midnapore district the badly degraded sal forests were revived with the involvement and participation of local villagers. The villagers were in return given employment and were allowed to collect firewood and fuelwood at a nominal fee.

Question 11.
Why are forests considered ‘biodiversity hot spots’? What would happen due to loss of biodiversity?
Answer:
Wide variety of plants, animals, microorganisms are found in forests. So they act as biodiversity hotspots. Loss of biodiversity disturbs ecological balance.

Question 12.
Prepare a list of five items that you use daily in the school. Identify from the list such items that can be recycled. (NCERT Exemplar)
Answer:
Paper, Plastic pencil box or Tiffin box, Steel spoon, Scale, Eraser.

Question 13.
List two advantages associated with water harvesting at the community level.  (NCERT Exemplar)
Answer:

1. Recharging of wells leads to increase in ground water level.
2. Ground water does not evaporates and keeps the layers of soil above it moist.
3. The water stored during rainy season can be used when required.

Question 14.
What measures would you take to conserve electricity in your house?  (NCERT Exemplar)
Answer:

• Switch off the fans and lights when they are not required.
• Use solar water heaters during winters.
• Use LED lights instead of normal bulbs or tube lights.

Question 15.
Although coal and petroleum are produced by degradation of biomass, yet we need to conserve them. Why? (NCERT Exemplar)
Answer:
It takes millions of years to form coal and petroleum and their reserves are limited. Due to this they would get exhausted very soon if utilised at a faster rate. Hence, they should be conserved for the needs of the future generations too.

Question 16.
Suggest a few measures for controlling carbon dioxide levels in the atmosphere.  (NCERT Exemplar)
Answer:

• Plant more and more trees.
• Using cleaner fuels like CNG.
• Make manure from litter instead of burning it.
• The harmful effluents from industries should be treated before discharging them into the atmosphere.
• Less use of fossil fuels.

Extra Questions for Class 10 Science Chapter 16 Short Answer Type II

Question 1.
What are natural resources? State two factors that work against an equitable distribution of these resources. (CBSE 2009)
Answer:
The stock of nature such as air, water, soil, minerals, forests and wildlife are called as natural resources. The two factors that work against their equitable distribution are

1. Overuse of resources and their overexploitation.
2. Human activities like cutting of trees, hunting, etc. which disturbs ecological balance.

Question 2.
What is water harvesting? Mention any two water harvesting structures.  (CBSE 2009)
Answer:
Capturing rainwater where it falls or capturing the run-off water so that it can be made available throughout the year for various purposes is called water harvesting.
Some traditional water harvesting structures are:

1. Khadins, tanks and nadis in Rajasthan
2. Kulhs in Himachal Pradesh.

Question 3.
How can we as an individual help in reducing the use of fossil fuels? Mention two ways.
Answer:
We can reduce the use of fossil fuels by .

1. Switching over to renewable sources of energy like solar energy, wind energy, etc.
2. Use public transport instead of private vehicles,
3. Ensure proper servicing and tuning of vehicles to increase fuel efficiency.

Question 4.
What is meant by exploitation of resources with short aims? List its four advantages.  (CBSE 2009)
Answer:
Use of resources for the benefit of a few rich and powerful people in order to fulfil short-term aims and the present needs is called exploitatation of resources with short aims. Its advantages are:

1. Maximises profit without any accountability.
2. Increases growth rate of economy for that duration.
3. They fulfil the needs of the present generation.
4. Ensures availability of a variety of raw materials for human use.

Question 5.
(a) List any two disadvantages of using fossil fuels for the production of energy.
(b) Give two examples each of the following:
(i) Renewable sources of energy. 3
(ii) Non-renewable sources of energy.  (CBSE 2011)
Answer:
(a) Disadvantages of using fossil fuels:

• The oxides of nitrogen and sulphur released on burning fossil fuels reacts with water vapour in air and falls in the form of harmful acid rain.
• Carbon dioxide released on burning them causes greenhouse effect which leads to global warming.
• Carbon monoxide releases on their combustion is toxic and can be fatal.
• They are limited, non-renewable resources which may get exhausted soon.

(b) (i) Examples of renewable sources of energy are

• Solar energy
• Wind energy

(ii) Examples of non-renewable sources of energy are

• Petrol
• Diesel

Question 6.
Dams are useful for the society but there is public opposition to the construction of large dams. Justify your answer by giving three problems.  (CBSE 2011)
Answer:

• Social problems: Large number of human settlements gets submerged in water during construction of dam.
• Environmental problems: Loss of vast variety of flora-fauna due to deforestation and biodiversity loss during construction of dams.
• Economic problems: Huge amount of public money is spent without getting proportionate benefits from such dams.

Question 7.
List the products of combustion of fossil fuels. What are their adverse effects on the environment?  (CBSE 2012)
Answer:
Carbon dioxide, sulphur dioxide, nitrogen oxide, water, carbon monoxide are the products of combustion of fossil fuels.
Their adverse effects on the environment are:

• Carbon dioxide is a greenhouse gas which leads to global warming.
• Oxides of nitrogen and sulphur react with water vapour present in air to form acids which fall in the form of acid rains and harms life.
• Carbon monoxide is a toxic gas which creates respiratory problems.

Question 8.
What is environmental planning? List any four human activities that are directly connected to influence the environment of a region.
Answer:
Various steps taken to reduce pollution and conserve natural resources for long term use is called environmental planning. It is necessary to maintain ecological balance. Human activities that are directly connected to influence the environment of a region are:

• Large scale deforestation for agricultural land or housing needs of growing population.
• Discharge of domestic wastes and industrial effluents into water bodies.
• Excessive use of fossil fuels which causes air pollution.
• Excessive use of non-biodegradable materials, plastics, detergents, etc. which harm the environment.

Question 9.
What is the full form of GAP? Why was it started? What is the main cause of abundant coliform in the river Ganga?
Answer:
GAP-Ganga Action Plan:
GAP was started to ensure the cleaning of water of river Ganga and reduce the pollution levels of Ganga. Main cause of abundant coliform bacteria in river Ganga is due to high amount of organic wastes disposed in the form of unburnt corpses into the water.

Question 10.
In a village in Karnataka, people started cultivating crops all around a lake which was always filled with water. They added fertilisers to their field in order to enhance the yield. Soon they discovered that the waterbody was completely covered with green floating plants and fishes started dying in large numbers.
Analyse the situation and give reasons for excessive growth of plants and death of fish in the lake. (NCERT Exemplar)
Answer:
The fertilisers containing high amount of phosphates and nitrates got carried down by rainwater into the lake which led to nutrient enrichment of water in lakes. This caused excessive growth of aquatic plants which ultimately covered the whole surface of the water body. Due to this insufficient amount of light entered the water body and levels of oxygen became low. This led to death of fishes in the water body.

Question 11.
(a) Locate and name the water reservoirs in Figures (a) and (b).
(b) Which has an advantage over the other and why?


Answer:
(a) The water reservoir in Figure (a) is a pond.
The water reservoir in Figure (b) is an underground water body.

(b) Figure (b) has more advantage than Figure (a), because the advantages of water stored in the ground are many. For example

• It does not evaporate.
• Spreads out to recharge wells and provides moisture for vegetation over a wide area.
• Does not provide breeding grounds for mosquitoes like stagnant water.

Extra Questions for Class 10 Science Chapter 16 Long Answer Type

Question 1.
What is a dam? Write two main advantages and two ill-effects of constructing big dam.  (CBSE 2009)
Answer:
Dams are constructed across the rivers to regulate the flow of water and store the huge amounts of water in large reservoirs. This ensures the supply of water for irrigation and other purposes.

Advantages of Dams:

• Ensures water availability for irrigation of fields.
• Water can be used to generate electricity in Hydel power stations by using turbines.

Disadvantages of dams:

• Social problems: Human settlements get submerged under water.
• Environmental problems: Large scale loss of biodiversity and deforestation.
• Economic problems: Huge amount of public money utilised in their construction but benefits are not proportionate.

Question 2.
Define Reduce, Recycle and Reuse with reference to the environment. Which is better strategy among recycle and reuse? Why?
Answer:
Recycle: Recycling wastes like paper, plastic and glass to obtain materials for use.
Reduce: Minimise the use of natural resources.
Reuse: Encourage the use of things again and again instead of throwing them away.
Reuse is better than recycling.

Recycling requires large amount of energy and money whereas reuse does not require any energy. So, reuse is better than recycling.

Question 3.
Prepare a list of five activities that you perform daily in which natural resources can be conserved or energy utilisation can be minimised.  (NCERT Exemplar)
Answer:

• Taking a bus, public transport or walking/cycling instead of a private vehicle.
• Using LED bulbs in homes instead of normal bulbs.
• Talking the stairs instead of lift.
• Using fan and light only when required.
• Using solar water heating devices.

Question 4.
Is water conservation necessary? Give reasons.  (NCERT Exemplar)
Answer:
The total amount of fresh water is more than enough to meet the needs of human beings. But due to its uneven distribution, wide seasonal, as well as yearly fluctuation in rainfalls and wastage, water shortage is a chronic problem inmost parts of the world.

Management of Natural Resources HOTS Questions With Answers

Question 1.
What is meant by ‘Sustainable Management’? The environmentalists are insisting upon sustainable natural resources management. State its four advantages.  (CBSE 2009)
Answer:
The judicious and wise use of resources to cater to the current basic needs and preserving the resources for the needs of the future generations is called sustainable management. Its advantages are:

1. Prevents exploitation of resources for short term gains and targets the long term aims.
2. Ensures equitable distribution of resources.
3. Minimises the harm caused to the environment.
4. Ensures the availability of resources for their use by the future generations in order to fulfil their needs.

Question 2.
With the help of an example show that ‘reuse’ strategy is better than recycling.  (CBSE 2010)
Answer:
Recycling involves use of energy and money whereas no energy is used in ‘reuse’, so reuse is better than recycling.

For example,
The plastic bottles can be recycled by heating them and remoulding them into different shapes. But, this would require the use of energy resources for getting heat required for remoulding plastic. Also, cost of the energy resource will have to be met. Instead of this, the plastic bottles can be reused for different purposes which will save both money and energy.

Question 3.
Prejudice against traditional use of forests areas has no basis. Explain with an example.
Answer:
Local people were not allowed by the Government to use the forests in the traditional ways they had been using for generations. This has led to harmful effects on the sustainability of forests and its resources. A striking example of such case is: Nomadic shepherds used to take their sheep for grazing in the alpine meadows of Great Himalayan Peak during summers. But when they were not allowed to take sheep for grazing, it was seen that grass in the region grew very tall and then fell over preventing fresh growth, which proved harmful for the biodiversity of the region.

Question 4.
Suggest a few useful ways of utilising waste water.  (NCERT Exemplar)
Answer:
Ways of utilising waste water are:

• Ground water level can be recharged.
• Can be used for construction purposes.
• Washing cars and watering gardens by treated waste water.
• Organic wastes in waste water may be used as fertilisers for crops.

Question 5.
What is the importance of forest as a resource?  (NCERT Exemplar)
Answer:
Forest are important as a resources because they

• Provide shelter and food to wildlife.
• Maintain balance of oxygen and carbon dioxide in the atmosphere.
• Increase water holding capacity of soil and prevent soil erosion.
• Help to regulate the water cycle.
• Products like fuel, wood, timber, paper, etc. are obtained.
• Products like fruits, resins, gums, essential oils, etc. used in various industries are obtained.

Question 6.
Why are the Arabari forests of Bengal known to be a good example of conserved forest?  (NCERT Exemplar)
Answer:
Due to efforts of forest officer A.K. Banerjee, the Sal forests in Arabari forests of West Bengal were revived with the active participation of the local people in their conservation. In return the villagers were given employment in both silviculture and harvesting operations, 25 per cent of the final harvest, and allowed fuel wood and fodder collection on payment of a nominal fee.

By 1983, due to the active and willing participation of the villagers, the previously worthless Sal forests in Arabari forest range of Midnapore district Underwent a remarkable recovery and were valued ₹ 12.5 crores.

Extra Questions for Class 10 Science Chapter 16 Value Based Questions

Question 1.
An environmentalist on visit to your school suggested the use of three R’s to save the environment. Explain what he meet by three R’s and how would you follow his advice at home. What values will be evident in this? (CBSE 2009)
Answer:
The three R’s are Reduce, Recycle and Reuse.
Reduce: It means to minimise the use of natural resources.
Recycle: It means to recycle the wastes to obtain materials again for use.
Reuse: It means to use the things again and again instead of throwing them way.

We would follow his advice at home by reducing use of fossil fuels, recycle the non-biodegradable materials and reuse the plastic and glass bottles of jams and pickles.
The values evident are: Awareness, Eco-friendly care for Nature and environment, Scientific aptitude.

Question 2.
Subhash has started the project of constructing his building. His architect suggested that he should add a system of rainwater harvesting in his building. He thought by adopting water harvesting in his project, he can solve his water crisis problem in the years to come.
(i) Is Subhash correct in his approach? Support your answer.
(ii) Give the values shown by Subhash.  (CBSE 2012)
Answer:
(i) Yes, Subhash is correct in adopting water harvesting in his project because the rainwater falling on the roof can be collected and used for recharging the ground water instead of flowing into drains. This would increase the ground water as it neither evaporates nor acts a breeding ground for mosquitoes like the water stored on surface. It also does not get contaminated by the human or animal wastes.

(ii) The values shown by Subhash:

• Scientific aptitude, Decision-Making
• Environment Friendly, Care for Nature.

Here we are providing Probability Class 10 Extra Questions Maths Chapter 15 with Answers Solutions, Extra Questions for Class 10 Maths was designed by subject expert teachers.

Extra Questions for Class 10 Maths Probability with Answers Solutions

Extra Questions for Class 10 Maths Chapter 15 Probability with Solutions Answers

Probability Class 10 Extra Questions Very Short Answer Type

Question 1.
State true or false and give the reason. If I toss a coin 3 times and get head each tir ne, then I should expect a tail to have a higher chance in the 4th toss.
Solution:
False, because the outcomes ‘head’ and ‘tail are equally likely. So, every time the probability of getting head or tail is \(\frac{1}{2}\)

Question 2.
A bag contains slips numbered from 1 to 100. If Fatima chooses a slip at random from the bag, it will either be an odd number or an even number. Since, this situation has only two possible outcomes, so the probability of each is \(\frac{1}{2}\) Justify.
Solution:
True, because the outcomes odd number’ and `even number’ are equally likely here.

Question 3.
In a family, having three children, there may be no girl, one girl, two girls or three girls. So, the probability of each is \(\frac{1}{4}\). Is this correct? Justify your answer.
Solution:
False, because the outcomes are not equally, likely. For no girl, outcome is bbb, for one girl, it is
bgb, gbb, bbg, for two girls, it is bgg, ggb, gbg and for all girls, it is ggg.

Question 4.
A game consists of spinning an arrow which comes to rest pointing at one of the regions (1, 2 or 3) (Fig. 15.1). Are the outcomes 1, 2 and 3 equally likely to occur? Give reason.
Solution:

False, because the outcome 3 is more likely than the other numbers.

Question 5.
Two coins are tossed simultaneously. Find the probability of getting exactly one head.
Solution:
Possible outcomes are {HH, HT, TH, TT}.
(exactly one head) = \(\frac{2}{4}\) = \(\frac{1}{2}\)

Question 6.
From a well shuffled pack of cards, a card is drawn at random. Find the probability of getting a black queen.
Solution:
Number of black queens in a pack of cards = 2
∴ P (black queen) = \(\frac{2}{52}\) = \(\frac{1}{26}\)

Question 7.
If P (E) = 0.05, what is the probability of ‘not E’ ?
Solution:
As we know that,
P (E) + P (not E) = 1
P (not E) = 1 – P (E) = 1 – 0.05 = 0.95

Question 8.
What is the probability of getting no head when two coins are tossed simultaneously?
Solution:
Favourable outcome is TT;
∴ P (no head) = \(\frac{1}{4}\)

Question 9.
In a single throw of a pair of dice, what is the probability of getting the sum a perfect square?
Solution:
Total outcomes = 36
Favourable outcomes are {(1,3), (3, 1), (2, 2), (3, 6), (6,3), (4, 5), (5, 4)}
∴ Required probability = \(\frac{7}{36}\)

Question 10.
Someone is asked to choose a number from 1 to 100. What is the probability of it being a prime number?
Solution:
Total prime numbers between 1 to 100 = 25
∴ P (Prime number) = \(\frac{25}{100}\) = \(\frac{1}{4}\)

Question 11.
Cards marked with number 3, 4, 5, …., 50 are placed in a box and mixed thoroughly. A card is drawn at random from the box. Find the probability that the selected card bears a perfect square number.
Solution:
Possible outcomes are 4, 9, 16, 25, 36, 49, i.e., 6.
∴ P (perfect square number) = \(\frac{6}{48}\) or \(\frac{1}{8}\)

Question 12.
A card is drawn at random from a well shuffled pack of 52 playing cards. Find the probability of getting neither a red card nor a queen.
Solution:
Number of possible outcomes = 52
Number of red cards and queens = 28
Number of favourable outcomes = 52 – 28 = 24
P (getting neither a red card nor a queen) = \(\frac{24}{52}\) = \(\frac{6}{13}\)

Question 13.
20 tickets, on which numbers 1 to 20 are written, are mixed throughly and then a ticket is drawn at random out of them. Find the probability that the number on the drawn ticket is a multiple of 3 or 7.
Solution:
n(s) = 20, Multiples of 3 or 7, A: {3, 6, 9, 12, 15, 18, 7, 14), n(A) = 8
∴ Required probability = \(\frac{8}{20}\) or \(\frac{2}{5}\)

Question 14.
A number is chosen at random from the numbers -3, -2, -1, 0, 1, 2, 3. What will be the probability that square of this number is less then or equal to 1?
Solution:
Favourable outcomes are -1, 0, 1 = 3
Total outcomes = 7
∴ Required probability = \(\frac{3}{7}\)

Probability Class 10 Extra Questions Short Answer Type 1

Question 1.
Two dice are thrown at the same time and the product of numbers appearing on them is noted. Find the probability that the product is a prime number.
Solution:
Product of the number on the dice is prime number, i.e., 2, 3, 5.
The possible ways are, (1, 2), (2, 1), (1, 3), (3, 1), (5, 1), (1, 5)
So, number of possible ways = 6
∴ Required probability = \(\frac{6}{36}\) = \(\frac{1}{6}\)

Question 2.
Find the probability that a number selected from the numbers 1 to 25 is not a prime number when each of the given numbers is equally likely to be selected.
Solution:
Total prime numbers from 1 to 25 = 9.
∴ Non-prime numbers from 1 to 25 = 25 – 9 = 16.
⇒ P (non-prime number) = \(\frac{16}{25}\)

Question 3.
One card is drawn at random from a pack of 52 cards. Find the probability that the card drawn is an ace and black.
Solution:
Number of black aces in a pack of cards = 2
∴ P (an ace and black card) = \(\frac{2}{52}\) = \(\frac{1}{26}\)

Question 4.
A card is drawn at random from a pack of 52 playing cards. Find the probability that the card drawn is neither an ace nor a king.
Solution:
Let E be the event card drawn is neither an ace nor a king.
Then, the number of outcomes favourable to the event E = 44 (4 kings and 4 aces are not there)
∴ P(E) = \(\frac{44}{52}\) = \(\frac{11}{13}\)

Question 5.
A bag contains lemon flavoured candies only. Malini takes out one candy without looking into the bag. What is the probability that she takes out (i) an orange flavoured candy? (ii) a lemon flavoured candy?
Solution:
(i) As the bag contains only lemon flavoured candies. So, the event related to the experiment of taking out an orange flavoured candy is an impossible event. So, its probability is 0.

(ii) As the bag contains only lemon flavoured candies. So, the event related to the experiment of taking out lemon flavoured candies is certain event. So, its probability is 1.

Question 6.
12 defective pens are accidentally mixed with 132 good ones. It is not possible to just look at a pen and tell whether or not it is defective. One pen is taken out at random from this lot. Determine the probability that the pen taken out is a good one.
Solution:
Here, total number of pens = 132 + 12 = 144
∴ Total number of elementary outcomes = 144
Now, favourable number of elementary events = 132
∴ Probability that a pen taken out is good one = \(\frac{132}{144}\) = \(\frac{11}{12}\)

Question 7.
Two players, Sangeeta and Reshma, play a tennis match. It is known that the probability of Sangeeta’s winning the match is 0.62. What is the probability of Reshma’s winning the match?
Solution:
Let S and R denote the events that Sangeeta and Reshma wins the match, respectively.
The probability of Sangeeta’s winning = P(S) = 0.62
As the events R and S are complementary
∴ The probability of Reshma’s winning = P(R) = 1 – P(S)
= 1 – 0.62 = 0.38.

Question 8.
A child has a die whose six faces show the letters as given below:

The die is thrown once. What is the probability of getting (i) A? (ii) D?
Solution:
The total number of elementary events associated with random experiment of throwing a die is 6.
(i) Let E be the event of getting a letter A.
∴ Favourable number of elementary events = 2
∴ P(E) = \(\frac{2}{6}\) = \(\frac{1}{3}\)
(ii) Let E be the event of getting a letter D.
∴ Favourable number of elementary events = 1
∴ P(E) = \(\frac{1}{6}\)

Question 9.
A card is drawn at random from a pack of 52 playing cards. Find the probability that the card drawn is neither a red card nor a black king.
Solution:
Let E be the event card drawn is neither a red card nor a black king’
The number of outcomes favourable to the event E = 24 (26 red cards and 2 black kings are not there, so 52 – 28 = 24)
∴ P(E) = \(\frac{24}{52}\) = \(\frac{16}{13}\)

Question 10.
Out of 400 bulbs in a box, 15 bulbs are defective. One bulb is taken out at random from the box. Find the probability that the drawn bulb is not defective.
Solution:
Total number of bulbs in the box = 400
Total number of defective bulbs in the box = 15
Total number of non-defective bulbs in the box = 400 – 15 = 385

Question 11.
Rahim tosses two different coins simultaneously. Find the probability of getting at least one
tail.
Solution:
The sample space is {HH, HT, TH, TT}
Total number of outcomes = 4
Outcomes for getting at least one tail is {HT, TH, TT}
Number of favourable outcomes = 3

= \(\frac{3}{4}\)

Probability Class 10 Extra Questions Short Answer Type 2

Question 1.
Harpreet tosses two different coins simultaneously (say, one is of 1 and other of 2). What is the probability that she gets at least one head?
Solution:
When two coins are tossed simultaneously, the possible outcomes are (H, H), (H, T), (T, H), (T, T) which are all equally likely. Here (H, H) means head up on the first coin (say on ₹ 1) and head up on the second coin (₹ 2). Similarly (H, T) means head up on the first coin and tail up on the second coin and so on.
The outcomes favourable to the event E, ‘at least one head’ are (H, H), (H, T) and (T, H). So, the number of outcomes favourable to E is 3.
Therefore, P(E) = \(\frac{3}{4}\)
i.e., the probability that Harpreet gets at least one head is \(\frac{3}{4}\).

Question 2.
A game consists of tossing a one-rupee coin 3 times and noting the outcome each time. Ramesh wins the game if all the tosses give the same result (i.e. three heads or three tails) and loses otherwise. Find the probability of Ramesh losing the game.
Solution:
The outcomes associated with this experiment are given by
HHH, HHT, HTH, THH, TTH, THT, HTT, TTT
∴ Total number of possible outcomes = 8
Now, Ramesh will lose the game if he gets
HHT, HTH, THH, TTH, THT, HTT
∴ Favourable number of events = 6
∴ Probability that he lose the game = \(\frac{6}{8}\) = \(\frac{3}{4}\)

Question 3.
Three unbiased coins are tossed together. Find the probability of getting:
(i) all heads.
(ii) exactly two heads.
(iii) exactly one head.
(iv) at least two heads.
(v) at least two tails
Solution:
Elementary events associated to random experiment of tossing three coins are
HHH, HHT, HTH, THH, HTT, THT, TTH, TTT
∴ Total number of elementary events = 8

(i) The event “getting all heads” is said to occur, if the elementary event HHH occurs, i.e., HHH is an outcome.
∴ Favourable number of elementary events = 1
Hence, required probability = \(\frac{1}{8}\)

(ii) The event “getting two heads” will occur, if one of the elementary events HHT, THH, HTH occurs.
∴ Favourable number of elementary events = 3
Hence, required probability = \(\frac{3}{8}\)

(iii) The event of “getting one head”, when three coins are tossed together, occurs if one of the elementary events HTT, THT, TTH, occurs.
Favourable number of elementary events = 3
Hence, required probability = \(\frac{3}{8}\)

(iv) If any of the elementary events HHH, HHT, HTH, and THH is an outcome, then we say that
the event “getting at least two heads” occurs.
∴ Favourable number of elementary events = 4
honom 4 Hence, required probability = \(\frac{4}{8}\) = \(\frac{1}{2}\)

(v) Similar as (iv) P (getting at least two tails) = \(\frac{4}{8}\) = \(\frac{1}{2}\)

Question 4.
A die is thrown once. Find the probability of getting:
(i) a prime number.
(ii) a number lying between 2 and 6.
(iii) an odd number.
Solution:
We have, the total number of possible outcomes associated with the random experiment of throwing a die is 6 (i.e., 1, 2, 3, 4, 5, 6).
(i) Let E denotes the event of getting a prime number.
So, favourable number of outcomes = 3 (i.e., 2, 3, 5)
∴ P(E) = \(\frac{3}{6}\) = \(\frac{1}{2}\)
(ii) Let E be the event of getting a number lying between 2 and 6.
∴ Favourable number of elementary events (outcomes) = 3 (i.e., 3, 4, 5)
∴ P(E) = \(\frac{3}{6}\) = \(\frac{1}{2}\)
(iii) Let E be the event of getting an odd number.
∴ Favourable number of elementary events = 3 (i.e., 1, 3, 5)
∴ P(E) = \(\frac{3}{6}\) = \(\frac{1}{2}\)

Question 5.
Suppose we throw a die once.
(i) What is the probability of getting a number greater than 4?
(ii) What is the probability of getting a number less than or equal to 4?
Solution:
(i) Here, let E be the event getting a number greater than 4′. The number of possible outcomes are six : 1, 2, 3, 4, 5 and 6, and the outcomes favourable to E are 5 and 6. Therefore, the number of outcomes favourable to E is 2. So,
P(E) = P (number greater than 4) = \(\frac{2}{6}\) = \(\frac{1}{3}\)
(ii) Let F be the event ‘getting a number less than or equal to 4’.
Number of possible outcomes = 6
Outcomes favourable to the event F are 1, 2, 3, 4.
So, the number of outcomes favourable to F is 4.
Therefore, P(F) = \(\frac{4}{6}\) = \(\frac{2}{3}\)

Question 6.
One card is drawn from a well-shuffled deck of 52 cards. Calculate the probability that the card will:
(i) be an ace.
(ii) not be an ace.
Solution:
Well-shuffling ensures equally likely outcomes.
(i) There are 4 aces in a deck. Let E be the event ‘the card is an ace’.
The number of outcomes favourable to E = 4.
The number of possible outcomes = 52
Therefore, P(E) = \(\frac{4}{52}\) = \(\frac{1}{3}\).
(ii) Let Ē be the event ‘card drawn is not an ace’.
The number of outcomes favourable to the event Ē = 52 – 4 = 48.
The number of possible outcomes = 52.
Therefore, P(Ē) = \(\frac{48}{52}\) = \(\frac{12}{13}\)

Question 7.
Five cards – the ten, jack, queen, king and ace of diamonds, are well-shuffled with their face downwards. One card is then picked up at random.
(i) What is the probability that the card is the queen?
(ii) If the queen is drawn and put aside, what is the probability that the second card picked up is (a) an ace? (b) a queen?
Solution:
Here, the total number of possible outcomes = 5.
(i) Since, there is only one queen
∴ Favourable number of elementary events = 1
∴ Probability of getting the card of queen = \(\frac{1}{5}\)

(ii) Now, the total number of possible outcomes = 4.
(a) Since, there is only one ace
∴ Favourable number of elementary events = 1
∴ Probability of getting an ace card = \(\frac{1}{4}\)

(b) Since, there is no queen (as queen is put aside)
∴ Favourable number of elementary events = 0
∴ Probability of getting a queen = \(\frac{0}{4}\)

Question 8.
A box contains 5 red marbles, 8 white marbles and 4 green marbles. One marble is taken out of the box at random. What is the probability that the marble taken out will be (i) red ? (ii) white? (iii) not green?
Solution:
Here, total number of marbles = 17
∴ Total number of possible outcomes = 17.
(i) Since, there are 5 red marbles in the box.
∴ Favourable number of elementary events = 5
∴ Probability of getting red marble = \(\frac{5}{17}\)

(ii) Since, there are 8 white marbles in the box.
∴ Favourable number of elementary events = 8
∴ Probability of getting white marble = \(\frac{8}{17}\)

(iii) Since, there are 5 + 8 = 13 marbles which are not green in the box.
∴ Favourable number of elementary events = 13
∴ Probability of not getting a green marble = \(\frac{13}{17}\)

Question 9.
A bag contains 5 black, 7 red and 3 white balls. A ball is drawn from the bag at random. Find the probability that the ball drawn is:
(i) red.
(ii) black or white.
(iii) not black.
Solution:
Total number of balls = 5 + 7 + 3 = 15
Number of red balls = 7, Number of black or white = 5 + 3 = 8 balls
Number of not black = 7 + 3 = 10 balls

(1) P (red ball) = \(\frac{7}{15}\)
(ii) P (black or white ball) = \(\frac{8}{15}\)
(iii) P (not black ball) = \(\frac{10}{15}\) = \(\frac{2}{2}\)

Question 10.
A bag contains 5 red, 8 white and 7 black balls. A ball is drawn at random from the bag. Find the probability that the drawn ball is: (i) red or white. (ii) not black. (iii) neither white nor black.
Solution:
Total number of balls = 5 + 8 + 7 = 20
(i) P (red or white) = \(\frac{5+8}{20}\) = \(\frac{13}{20}\)
(ii) P (not black) = 1 – P (black) = 1 – \(\frac{7}{20}\) = \(\frac{13}{20}\)
(iii) P (neither white nor black) = P (Red balls) = \(\frac{5}{20}\) = \(\frac{1}{4}\)

Question 11.
It is given that in a group of 3 students, the probability of 2 students not having the same birthday is 0.992. What is the probability that the 2 students have the same birthday?
Solution:
Let E be the event of having the same birthday.
Therefore, Ē is the event of not having the same birthday.
i.e., P (Ē) = 0.992 (Given)
Now, we have
P(E) + P(Ē) = 1 ⇒ P(E) = 1 – P(E) = 1 -0.992 = 0.008.

Question 12.
1000 tickets of a lottery were sold and there are 5 prizes on these tickets. If Saket has purchased one lottery ticket, what is the probability of winning a prize ?
Solution:
Out of 1000 lottery tickets, one ticket can be chosen in 1000 ways.
∴ Total number of elementary events = 1000
It is given that there are 5 prizes on these 1000 tickets.
Therefore, number of ways of selecting a prize ticket = 5 .
∴ Favourable number of elementary events
Hence, P (Winning a prize) = \(\frac{5}{1000}\) = \(\frac{1}{200}\)

Question 13.
In a single throw of a pair of different dice, what is the probability of getting (i) a prime number on each dice ? (ii) a total of 9 or 11 ?
Solution:
Total outcomes = 36
(i) Favourable outcomes are (2, 2) (2, 3) (2, 5) (3, 2) (3, 3) (3, 5) (5, 2) (5, 3) (5, 5) i.e., 9 outcomes.
P (a prime number on each die) = \(\frac{9}{36}\) or \(\frac{1}{4}\)
(ii) Favourable outcomes are (3,6) (4, 5) (5, 4) (6, 3) (5, 6) (6, 5) i.e., 6 outcomes
P (a total of 9 or 11) = \(\frac{6}{36}\) or \(\frac{1}{6}\)

Question 14.
Two different dice are thrown together. Find the probability that the numbers obtained
(i) have a sum less than 7
(ii) have a product less than 16
(iii) is a doublet of odd numbers.
Solution:
Total number of outcomes = 36
(i) Favourable outcomes are
(1, 1,) (1, 2) (1, 3) (1, 4) (1,5) (2, 1) (2, 2) (2, 3)
(2, 4) (3, 1) (3, 2) (3, 3) (4, 1) (4, 2) (5, 1) i.e., 15
∴ P (sum less than 7) = \(\frac{15}{36}\) or \(\frac{5}{12}\)
(ii) Favourable outcomes are
(1, 1) (1, 2) (1,3) (1, 4) (1,5) (1,6) (2, 1) (2, 2) (2,3)
(2, 4) (2,5) (2, 6) (3, 1) (3, 2) (3, 3) (3, 4) (3,5) (4, 1)
(4, 2) (4, 3) (5, 1) (5, 2) (5, 3) (6, 1) (6, 2) i.e., 25
∴ P (product less than 16) = \(\frac{25}{36}\)
(iii) Favourable outcomes are
(1, 1) (3, 3) (5, 5) 1.e, 3
∴ (doublet of odd number) = \(\frac{3}{36}\) or \(\frac{1}{12}\)
3 or 1

Probability Class 10 Extra Questions Long Answer Type

Question 1.
One card is drawn from a well-shuffled deck of 52 cards. Find the probability of getting:
(i) a king of red colour.
(ii) a face card.
(iii) a red face card.
(iv) the jack of hearts.
(v) a spade.
(vi) the queen of diamonds.
Solution:
Here, total number of possible outcomes = 52
(i) As we know that there are two suits of red card, i.e., diamond and heart and each suit contains one king.
∴ Favourable number of outcomes = 2
∴ Probability of getting a king of red colour = \(\frac{2}{52}\) = \(\frac{1}{26}\)

(ii) As we know that kings, queens and jacks are called face cards. Therefore, there are 12 face cards.
∴ Favourable number of elementary events = 12
∴ Probability of getting a face card = \(\frac{12}{52}\) = \(\frac{3}{13}\)

(iii) As we know there are two suits of red cards, i.e., diamond and heart and each suit contains 3 face cards.
∴ Favourable number of elementary events = 2 × 3 = 6
∴ Probability of getting red face card = \(\frac{6}{52}\) = \(\frac{3}{26}\)

(iv) Since, there is only one jack of hearts.
∴ Favourable number of elementary events = 1
∴ Probability of getting the jack of heart = \(\frac{1}{52}\)

(v) Since, there are 13 cards of spade.
∴ Favourable number of elementary events = 13
∴ Probability of getting a spade = \(\frac{13}{52}\) = \(\frac{1}{4}\)

(vi) Since, there is only one queen of diamonds.
∴ Favourable number of outcomes (elementary events) = 1
∴ Probability of getting a queen of diamond = \(\frac{1}{52}\)

Question 2.
One card is drawn from a pack of 52 cards, each of the 52 cards being equally likely to be drawn. Find the probability that the card drawn is:
(i) an ace.
(ii) red.
(iii) either red or king.
(iv) red and a king.
(v) a face card.
(vi) a red face card.
(vii) “2′ of spades.
(viii) ’10’ of a black suit.
Solution:
Out of 52 cards, one card can be drawn in 52 ways.
So, total number of elementary events = 52
(i) There are four ace cards in a pack of 52 cards. So, one ace can be chosen in 4 ways.
∴ Favourable number of elementary events = 4
Hence, required probability = \(\frac{4}{52}\) = \(\frac{1}{13}\)

(ii) There are 26 red cards in a pack of 52 cards. Out of 26 red cards, one card can be chosen in 26 ways.
∴ Favourable number of elementary events = 26
Hence, required probability = \(\frac{26}{52}\) = \(\frac{1}{2}\)

(iii) There are 26 red cards, including two red kings, in a pack of 52 playing cards. Also, there are 4 kings, two red and two black. Therefore, card drawn will be a red card or a king if it is any one of 28 cards (26 red cards and 2 black kings).
∴ Favourable number of elementary events = 28
Hence, required probability = \(\frac{28}{52}\) = \(\frac{7}{13}\)

(iv) A card drawn will be red as well as king, if it is a red king. There are 2 red kings in a pack of 52 playing cards.
∴ Favourable number of elementary events = 2
Hence, required probability = \(\frac{2}{52}\) = \(\frac{1}{26}\)

(v) In a deck of 52 cards: kings, queens, and jacks are called face cards. Thus, there are 12 face cards. So, one face card can be chosen in 12 ways.
Favourable number of elementary events = 12
Hence, required probability = \(\frac{12}{52}\) = \(\frac{3}{13}\)

(vi) There are 6 red face cards 3 each from diamonds and hearts. Out of these 6 red face cards, one card can be chosen in 6 ways.
∴ Favourable number of elementary events = 6
Hence, required probability = \(\frac{6}{52}\) = \(\frac{3}{26}\)

(vii) There is only one ‘2’ of spades.
∴ Favourable number of elementary events = 1 Hence, required probability = 2

(viii) There are two suits of black cards viz. spades and clubs. Each suit contains one card bearing number 10.
∴ Favourable number of elementary events = 2
Hence, required probability = \(\frac{2}{52}\) = \(\frac{1}{26}\)

Question 3.
A game of chance consists of spinning an arrow which comes to rest pointing at one of the numbers 1,2,3,4,5,6,7,8 see Fig, and these are equally likely outcomes. What is the probability that it will point at: (i) 8? (ii) an odd number? (iii) a number greater than 2? (iv) a number less than 9?
Solution:

Here, total number of elementary events (possible outcomes) = 8
(i) We have only one ‘P’ on the spining plant.
∴ Favourable number of outcomes = 1
Hence, the probability that arrow points at 8 = \(\frac{1}{26}\).

(ii) We have four odd points (i.e., 1, 3, 5 and 7)
∴ Favourable number of outcomes = 4
∴ Probability that arrow points at an odd number = \(\frac{4}{8}\) = \(\frac{1}{2}\)

(iii) We have 6 numbers greater than 2, i.e., 3, 4, 5, 6, 7 and 8.
Therefore, favourable number of outcomes = 6
∴ Probability that arrow points at a number greater than 2 = \(\frac{6}{8}\) = \(\frac{3}{4}\)

(iv) We have 8 numbers less than 9, i.e, 1, 2, 3, … 8.
∴ Favourable number of outcomes = 8
∴ Probability that arrow points at a number less than 9 = \(\frac{8}{8}\) = 1.

Question 4.
Two dice, one blue and one grey, are thrown at the same time. Write down all the possible outcomes. What is the probability that the sum of the two numbers appearing on the top of the dice is: (i) 8? (ii) 13? (iii) less than or equal to 12?
Solution:
When the blue die shows ‘l’, the grey die could show any one of the numbers 1, 2, 3, 4, 5, 6.
The same is true when the blue die shows ‘2’, ‘3’, ‘4’, ‘5’ or ‘6’. The possible outcomes of the experiment are listed in the table below; the first number in each ordered pair is the number appearing on the blue die and the second number is that on the grey die. So, the number of possible outcomes = 6 × 6 = 36.

(i) The outcomes favourable to the event the sum of the two numbers is 8′ denoted by E, are :
(2, 6), (3, 5), (4, 4), (5, 3), (6, 2) (see figure)
i.e., the number of outcomes favourable to E = 5.
Hence, P(E) = \(\frac{5}{36}\)

(ii) As you can see from figure, there is no outcome favourable to the event F, ‘the sum of two numbers is 13’.
So, P(F) = \(\frac{0}{36}\) = 0

(iii) As you can see from figure, all the outcomes are favourable to the event G, ‘sum of two numbers ≤ 12.
So, P(G) = \(\frac{36}{36}\) = 1.

Question 5.
A bag contains cards numbered from 1 to 49. A card is drawn from the bag at random, after mixing the cards throughly. Find the probability that the number on the drawn card is:
(i) an odd number.
(ii) a multiple of 5.
(iii) a perfect square.
(iv) an even prime number.
Solution:
Total number of cards = 49
Total number of outcomes = 49
(i) Odd number
Favourable outcomes : 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49
Number of favourable outcomes = 25

Question 6.
All the black face cards are removed from a pack of 52 playing cards. The remaining cards are well shuffled and then a card is drawn at random. Find the probability of getting a:
(i) face card.
(ii) red card.
(iii) black card.
(iv) king.
Solution:
Cards remaining after removing black face cards = red cards + black cards excluding face cards
= 26 + 20 = 46
Total number of possible outcomes = 46
(i) Face Card
Favourable outcomes: 6 red face cards (king, queen and jack of diamond and heart suits)

Question 7.
Cards numbered from 11 to 60 are kept in a box. If a card is drawn at random from the box, find the probability that the number on the drawn card is:
(i) an odd number.
(ii) a perfect square number.
(iii) divisible by 5.
(iv) a prime number less than 20.
Solution:
No. of possible outcomes = 60 – 11 + 1 = 50.
(i) An odd number
Favourable outcomes : 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59
No. of favourable outcomes = 25
Number of favourable outcomes

= \(\frac{25}{50}\) = \(\frac{1}{2}\)

(ii) A perfect square number
Favourable outcomes : 16, 25, 36, 49
No. of favourable outcomes = 04

= \(\frac{4}{50}\) = \(\frac{2}{25}\)

(iii) Divisible by 5
Favourable outcomes : 15, 20, 25, 30, 35, 40, 45, 50, 55, 60
No. of favourable outcomes = 10

= \(\frac{10}{50}\) = \(\frac{1}{5}\)

(iv) A prime number less than 20
Favourable outcomes : 11, 13, 17, 19
No. of favourable outcomes = 4

= \(\frac{4}{50}\) = \(\frac{2}{25}\)

Question 8.
A number x is selected at random from the numbers 1, 2, 3 and 4. Another number y is selected at random from the numbers 1, 4, 9 and 16. Find the probability that product of x and y is less than 16.
Solution:
x can be any one of 1, 2, 3 or 4.
y can be any one of 1, 4, 9 or 16
Total number of cases of product of x and y = 16
Product less than 16 = (1 × 1, 1 × 4, 1 × 9, 2 × 1, 2 × 4, 3 × 1, 3 × 4, 4 × 1)
Number of cases, where product is less than 16 = 8
∴ Required probability = \(\frac{8}{16}\) or \(\frac{1}{2}\)

Question 9.
In Fig, shown a disc on which a player spins an arrow twice. The function \(\frac{a}{b}\) is formed, where ‘a’ is the number of sector on which arrow stops on the first spin and ‘b’ is the number of the sector in which the arrow stops on second spin. On each spin, each sector has equal chance of selection by the arrow. Find the probability that the fraction \(\frac{a}{b}\) > 1.
Solution:

For alb > 1, when a = 1, b can not take any value,
a = 2, b can take 1 value,
a = 3, b can take 2 values,
a = 4, b can take 3 values,
a = 5, b can take 4 values,
a = 6, b can take 5 values.
Total possible outcomes = 36

Question 10.
Two different dice are thrown together. Find the probability that the numbers obtained have
(i) even sum, and (ii) even product.
Solution:
Total number of outcomes = 36[(1, 1), (1, 2) … (6,6)]
Number of outcomes when sum is even = 18 [(1, 1), (1, 3) …(6, 6)]
Number of outcomes when product is even = 27 [(1, 2), (1, 4) … (6,6)]

Probability Class 10 Extra Questions HOTS

Question 1.
A die is thrown twice. What is the probability that
(i) 5 will not come up either time?
(ii) 5 will come up at least once?
Solution:
(i) Favourable outcomes are
[(1, 1), (1, 2), (1, 3), (1, 4), (1, 6), (2, 1), (2, 2), (2, 3), (2, 4), (2, 6), (3, 1), (3, 2), (3, 3), (3, 4), (3,6), (4, 1), (4,2), (4, 3), (4, 4), (4, 6), (6, 1), (6, 2), (6, 3), (6, 4), (6, 6)]
Total outcomes = 36
∴ Required probability = \(\frac{25}{36}\)
(ii) Probability that 5 will come atleast once = 1 – P (5 will not come up either time)
= 1 – \(\frac{25}{36}\) = \(\frac{11}{36}\)

Question 2.
Find the probability that in a leap year there will be 53 Tuesdays.
Solution:
Leap year = 366 days = (52 × 7 + 2) days = 52 weeks and 2 days.
Thus, a leap year always has 52 Tuesdays. The remaining 2 days can be:

1. Sunday and Monday
2. Monday and Tuesday
3. Tuesday and Wednesday
4. Wednesday and Thursday
5. Thursday and Friday
6. Friday and Saturday
7. Saturday and Sunday

Out of these 7 cases, we have Tuesdays in two cases
∴ P(53 Tuesdays) = \(\frac{2}{7}\)

Question 3.
A bag contains 5 red balls and some blue balls. If the probability of drawing a blue ball from the bag is thrice that of a red ball, find the number of blue balls in the bag.
Solution:
Let there be x blue balls in the bag.
∴ Total number of balls in the bag = (5 + x)

Hence, there are 15 blue balls in the bag.

Question 4.
Apoorv throws two dice once and computes the product of the numbers appearing on the dice. Peehu throws one die and squares the number that appears on it. Who has the better chance of getting the number 36? Why?
Solution:
Apoorv throws two dice once.
So, total number of outcomes, n(S) = 36.
Number of outcomes for getting product 36,
n(E₂) = 1 [(6 × 6)]
∴ Probability for Apoorv getting the number 36

Also, Peehu throw one die.
So, total number of outcomes n(S) = 6
Number of outcomes for getting square of a number as 36.
n(E₂) = 1 (∵ 6² = 36)
∴ Probability for Peehu getting the number 36

Hence, Peehu has better chance of getting the number 36.

In this page, we are providing Our Environment Class 10 Extra Questions and Answers Science Chapter 15 pdf download. NCERT Extra Questions for Class 10 Science Chapter 15 Our Environment with Answers will help to score more marks in your CBSE Board Exams.

Class 10 Science Chapter 15 Extra Questions and Answers Our Environment

Extra Questions for Class 10 Science Chapter 15 Our Environment with Answers Solutions

Extra Questions for Class 10 Science Chapter 15 Very Short Answer Type

Question 1.
Give an example each of natural and an artificial ecosystem.
Answer:
Natural ecosystem : Forest or pond
Artificial ecosystem : Crop field or aquarium.

Question 2.
What is the full form of CFCs and UNEP?
Answer:
CFC = Chlorofluorocarbons
UNEP = United Nations Environment Programme.

Question 3.
Define ecosystem and name its components.
Answer:
The living and non-living components of an area interact with each other to form an ecosystem. Components of ecosystem are: Biotic (living) and abiotic (non-living)

Question 4.
What is the role of ozone? Why is it being depleted?
Answer:
Ozone protects us from harmful UV radiations. It is being depleted due to excess use of chlorofluorocarbons (CFCs).

Question 5.
What is ten per cent law?
Answer:
Ten per cent law states that only 10% of the energy available at a trophic level is transferred to the next trophic level.

Question 6.
List two advantage of decomposers to the environment.  [CBSE 2008]
Answer:
Advantage of decomposers:

1. They replenish the soil nutrients.
2. They help to clean the environment by degrading the dead remains of plants and animals.

Question 7.
What is the ultimate source of energy in an ecosystem? Which process helps to trap this energy in producers?
Answer:
Sun is the ultimate source of energy in an ecosystem. Photosynthesis helps to trap this energy in producers.

Question 8.
What is the major cause of ozone depletion? Where are these substances used?  [CBSE 2012]
Answer:
Chlorofluorocarbons are major cause of ozone depletion. They are used in refrigerator and aerosol sprays.

Question 9.
Why should biodegradable and non-biodegradable wastes to be discarded in two separate dustbins?  [CBSE 2015]
Answer:
Biodegradable and non-biodegradable waste should be discarded in two separate dustbins as it will make it easier to recycle the recyclable wastes. This will also save time and energy.

Question 10.
What will happen if we kill all the organisms in one trophic level?  [CBSE 2011]
Answer:
Killing all the organisms in one trophic level would decrease availability of food at the next trophic level and also result in excess of organisms at the previous trophic level. This would cause an imbalance in the food chain.

Extra Questions for Class 10 Science Chapter 15 Short Answer Type I

Question 1.
Arrange these organisms in a food chain Snake, Plants, Frog, Bird
Answer:
Plants → Frog → Snake → Bird

Question 2.
Draw an ecological pyramid, depicting the trophic levels.
Answer:

Question 3.
The first trophic level in a food chain is always a green plant. Why?  [CBSE 2015]
Answer:
Green plants contain a pigment called chlorophyll which traps the energy from the Sun and converts it into chemical energy to be utilised by the members of the next trophic level. So, the first trophic level in a food chain is always a green plant.

Question 4.
List two environment friendly practices or habits which need to be followed by every member of a family community. Explain how these practices will support the “save the environment” mission.  [CBSE 2014]
Answer:

1. Use of paper bags or jute bags instead of plastic bags.
2. Segregate biodegradable and non-biodegradable wastes in separate dustbins.
3. Use fuels like CNG, unleaded petrol or other ecofriendly fuels in vehicles.
   Due to uses of environment friendly practices or habits we can save our environment.

Question 5.
Write the harmful effects of using plastic bags on the environment. Suggest alternatives to plastic bags. [CBSE 2013]
Answer:
Harmful effects of plastic bags

• They clog the drainage system.
• They choke the alimentary canal of cattle when they get eaten by them.
• On burning they release toxic gases.
• They are non-biodegradable and do not decompose easily.

Alternative to plastic bags:

• Use of jute bags or paper bags.
• Reusable cloth bags.

Question 6.
Construct an aquatic food chain showing four trophic levels.  [CBSE 2010]
Answer:
Phytoplankton → Zooplankton → Small fish → Bird.

Question 7.
Why is improper disposal of waste a curse to the environment?  [NCERT Exemplar]
Answer:
The improper disposal of wastes pollutes our environment and can cause harm to living organisms.

Question 8.
What are the advantages of cloth bags over plastic bags during shopping?  [NCERT Exemplar]
Answer:
Cloth bags are better than the plastic bags because they:

• can be used to carry many things
• can be reused
• are made of biodegradable materials
• do not pollute the environment.

Question 9.
Why are crop fields known as artificial ecosystems?  [NCERT Exemplar]
Answer:
The crop fields are prepared and maintained by a man so they are man-made ecosystems. Hence, they are also called an artificial ecosystems.

Question 10.
We do not clean ponds or lakes, but an aquarium needs to be cleaned. Why? [NCERT Exemplar]
Answer:
A pond or a lake is a natural, self-sustaining, and complete ecosystem. But, an aquarium is an artificial and incomplete ecosystem that needs human intervention for its cleaning and upkeep.

Extra Questions for Class 10 Science Chapter 15 Short Answer Type II

Question 1.
Differentiate between biodegradable and non-biodegradable substances with the help of one example each. List two changes in habit that people must adapt to dispose non-biodegradable waste for saving the environment.  [CBSE 2015]
Answer:
1. Biodegradable substances: Substances that can be slowly destroyed and broken down into very small parts by natural processes by bacteria, fungi, etc. For example, organics wastes like vegetables and fruit peels.

2. Non-biodegradable substances: Substances that cannot be broken down or decomposed into the soil by natural agents are called as non-biodegradable. For example, plastic.
Habits to dispose non-biodegradable waste are:

• Segregating and treating the non-biodegradable waste before putting in dustbins.
• Recycle the plastics or glass present in non-biodegradable wastes.
• Motivate people to use paper or jute bags instead of plastic bags.

Question 2.
Our food grains such as wheat and rice, vegetables and fruits, and even meat are found to contain varying amounts of pesticide residues. State the reason to explain how and why it happens?  [CBSE 2014]
Answer:
The harmful pesticides like DDT enter the plant body on being absorbed from the soil. When these are eaten by animals they get accumulated in the animal’s body as they are neither metabolized nor excreted out of their body. The concentration of these harmful chemicals gets increased at successive levels and are thus found in food grains as well as meat.

Question 3.
How is ozone formed in the higher level of the atmosphere? “Damage to ozone layer is a cause of concern”. Justify this statement.  [CBSE 2010]
Answer:
Ozone is formed due to action of UV rays on oxygen molecules to form free oxygen atom which subsequently combines with another molecule of oxygen to form ozone. The reaction is:

O + O₂ → O₃ (Ozone)

Ozone depletion is a cause of concern because it protects us from the harmful ultraviolet radiations of the Sun by absorbing them. The UV rays can cause skin cancer, ageing, cataract, etc. to human beings if they are not absorbed by ozone due to ozone depletion.

Question 4.
Explain phenomenon of “biological magnification”. How does it affect organisms belonging to different trophic levels particularly the tertiary consumers?  [CBSE 2010]
Answer:
The levels of harmful toxicants/pesticides like DDT gets increased at successive trophic levels as they are neither metabolised nor excreted by the organism. They get accumulated in organism’s body with their higher concentrations at higher trophic levels. This is called as biological magnification.

Since, the tertiary consumers are at the top of the food chain, so a higher amount of these toxicants is present in them compared to the lower trophic levels.

Extra Questions for Class 10 Science Chapter 15 Long Answer Type

Question 1.
Suggest any four activities in daily life which are eco-friendly.  [NCERT Exemplar]
Answer:
The eco-friendly activities in life are

• Planting of trees.
• Segregating biodegradable and non-biodegradable wastes.
• Using cloth bags, jute bags or paper bags instead of plastic bags.
• Creating awareness on environment protection through initiatives and campaigns.
• Using of manures and organic agricultural methods.
• Using less of chemical fertilizers and pesticides.
• Controlling pollution by using fuels like CNG.

Question 2.
Make food chains in (i) forest (ii) grassland (iii) pond. How does food chain differ from a food web?
Answer:
Food chains in:
(i) Forest: Plants → Deer → Lion
(ii) Grassland: Plants → Grasshopper → Frog → Snake → Eagle
(iii) Pond: Aquatic plants → Scorpion Fish → Flamingo

Food Chain: It is a series of organisms feeding on one another.
Food Web: It is a network of food chains consisting of a number of interlinked food chains.

Question 3.
Indicate the flow of energy in an ecosystem. Why is it unidirectional?  [NCERT Exemplar]
Answer:
The flow of energy generally is
Sun → Producer → Herbivore → Carnivore

The flow of energy is unidirectional because it goes progressively from one trophic level (lower) to another trophic level (higher) and does not revert back.
It is impossible for energy to flow in the reverse direction as the available energy decreases in the higher trophic levels.

Question 4.
Name the wastes which are generated in your house daily. What measures would you take for their disposal? [NCERT Exemplar]
Answer:
The wastes generated in our house daily are:

• Kitchen wastes
• Paper wastes like newspapers, bags, envelopes
• Plastic bags
• Vegetable/fruit peels/rinds

The measures which can be taken for their disposal are:

• Segregate the wastes as biodegradable, non-biodegradable and hazardous ones.
• Dispose of the plastic bags and bottles in a proper way.
• Vegetable/fruit peels can be used to make compost.
• Paper wastes can be used for recycling.
• Prepare a vermicompost pit for the organic wastes from the kitchen.

Question 5.
What are the by-products of fertiliser industries? How do they affect the environment?  [NCERT Exemplar]
Answer:
The harmful by-products of fertiliser industries are the harmful gases like SO₂ and NO. They cause air pollution and combine with the water vapour in the atmosphere to cause harmful acid rain.

Question 6.
Explain some harmful effects of agricultural practices on the environment.  [NCERT Exemplar]
Answer:

• Change in the chemistry of soil and killing of useful microbes due to excessive use of fertilisers.
• Biological magnification occurs due to excessive use of chemical pesticides.
• Water table gets lowered due to the excess use of ground water.
• Soil fertility is lost due to extensive cropping.
• The natural ecosystems is harmed due to ploughing during agriculture.

Our Environment HOTS Questions With Answers

Question 1.
“Energy flow in a food chain is unidirectional”. Justify this statement. Explain how the pesticides enter a food chain and subsequently get into our body.  [CBSE 2014]
Answer:
The flow of energy in an ecosystem occurs from a lower trophic level to the next trophic level i.e., from producers to consumers. It follows the ten percent law and thus cannot return back to producers from consumers. Hence, the flow of energy in a food chain is unidirectional.

The pesticides like DDT enter the food chain after getting absorbed by plants from the soil. Once they enter the food chain, they are neither metabolized nor excreted from the body of the organism. Its concentration increases in the successive trophic level of the food chain.

Question 2.
In a food chain, if 10000 Joules of energy is available to the producer, how much energy will be available to the secondary consumer to transfer it to the tertiary consumer? [CBSE 2012]
Answer:
(i) Energy available to producers = 10,000 Joules.
Energy transfer to producer = 1% of 10,000 Joules = 100 Joules.

(ii) According to Ten per cent law,
Energy transfer to primary consumer = \(\frac{10}{100}\) × 100 = 10 Joules.

(iii) Energy transfer to secondary consumer = \(\frac{10}{100}\) × 10 = 1 Joule

(iv) Energy transfer to tertiary consumer = \(\frac{10}{100}\) × 1 = 0.1 Joule

Extra Questions for Class 10 Science Chapter 15 Value Based Questions

Question 1.
Rakshit observed a gardener collecting dry leaves from a garden and burning them. He went to the gardener and advised him to utilise the dry leaves for making manure instead of burning.
(a) Name the two process which can be used to make manures from the dry leaves.
(b) Why did Rakshit advise the gardener not to burn leaves?
(c) What are the values shown by Rakshit?
(d) Why are organic manure better than chemical fertilisers?
Answer:
(a) Composting and vermicomposting
(b) Burning of leaves emits smoke and harmful gases which pollute the environment.
(c) Environment friendly, concern for life, awareness, scientific attitude, logical thinking, etc.
(d) Organic manures are better than chemical fertilisers as excess use of chemical fertilisers leads to (i) loss in soil fertility (ii) increase in soil salinity.

Question 2.
The students of a school formed an Environment Club and started Campaign to Recycle waste, No cracker campaign and No-plastic campaign.
(а) What are the harmful effects of plastic waste?
(b) What are the alternatives to use of plastic bags?
(c) What are the values exhibited by the students of the school?
(d) Why is it necessary to recycle wastes?
Answer:
(a) The excess use of plastics causes the following problems:

• It causes environmental pollution.
• Plastic bags are non-biodegradable and can cause problems in the digestive system of animals if they eat these plastic bags.

(b) Alternatives are the use of Jute bags or paper bags.
(c) Values are: Eco-friendliness, Concern for life, Responsible, Creative thinking.
(d) To reduce the amount of garbage generated.

Question 3.
The Government of Delhi has proposed the odd-even formula for the use of cars on an alternate basis. The move is aimed at reducing the level of pollution in the city. Further, this move will also help in the conservation of fuel resources.
(a) Mention the values inherent in such a decision of the Government.
(b) What other options (any two) can be used to reduce the level of pollution in city?
(c) How can such a move help in conservation of fuel resources?
(d) How can we ensure lesser emission of pollutants from the vehicles?
Answer:
(a) Concern for environment, judicious use of energy resources, environmental health, concern and care for public health.
(b) Use of CNG as fuel, lesser use of diesel vehicles.
(c) The vehicles usually run on petrol and diesel which are non-renewable energy resources. This less use of these will help in their conservation.
(d)

• Strict pollution control norms.
• Better engines with higher fuel efficiency.
• Ensuring lesser emissions of exhaust gases from vehicles.
• Use of cleaner fuels like CNG.

In this page, we are providing Sources of Energy Class 10 Extra Questions and Answers Science Chapter 14 pdf download. NCERT Extra Questions for Class 10 Science Chapter 14 Sources of Energy with Answers will help to score more marks in your CBSE Board Exams.

Class 10 Science Chapter 14 Extra Questions and Answers Sources of Energy

Extra Questions for Class 10 Science Chapter 14 Sources of Energy with Answers Solutions

Extra Questions for Class 10 Science Chapter 14 Very Short Answer Type

Question 1.
Define fossil fuel.
Answer:
Fossil fuels were formed millions of years ago, when plants and animal remains got buried under the earth and were subjected to high temperature and pressure conditions. For example, Coal, Petroleum, etc.

Question 2.
Write down the disadvantages of fossil fuels.
Answer:
These fossil fuels are non-renewable sources of energy and cause environmental problems due to pollution.

Question 3.
Define Nuclear energy.
Answer:
Nuclear energy: Energy released when some changes take place in the nucleus of the atom of a substance, is called Nuclear energy.

Question 4.
Define solar cell.
Answer:
Solar cell is a device that converts solar energy into electricity.

Question 5.
Define non-conventional sources of energy.
Answer:
Non-conventional sources of energy are those which are not used as the conventional ones and meet our energy requirement only on a limited scale.
Examples:

• Tidal energy
• Geothermal energy.

Question 6.
Define conventional sources of energy.
Answer:
Conventional sources of energy are those which are used extensively and meet a major portion of our energy requirement.
Examples:

• Fossil fuels
• Hydropower plants.

Question 7.
How is charcoal produced and what is the advantage of charcoal in comparison to wood?
Answer:
When wood is burnt in a limited supply of oxygen, the volatile materials present in it get removed, and charcoal is produced. Charcoal bums without flames and is comparatively less smoky.

Extra Questions for Class 10 Science Chapter 14 Short Answer Type I

Question 1.
Write down the characteristics of a good fuel.
Answer:
Characteristics of a good fuel:

• Has high calorific value
• Produces less smoke
• Produces less residue after burning
• Easy availability
• Inexpensive
• Easy to store and transport

Question 2.
What is a thermal power plant?
Answer:
In a thermal power plant

• Coal, petroleum and natural gas is used to produce thermal electricity.
• Electricity transmission is very efficient.
• The steam produced by burning fossil fuels runs the turbine to produce electricity.

Question 3.
Write down the advantages and disadvantages of a nuclear power plant.
Answer:
Advantage of Nuclear energy:

• Alternative source of energy due to depletion of fossil fuels.
• From a small amount of fuel, a large amount of energy is released.

Disadvantages of nuclear energy:

• Difficult to store and dispose nuclear waste which may cause environmental contamination.
• High cost of setting up a nuclear plant.
• Limited availability of raw material (uranium).

Question 4.
Describe energy harnessed from wind and write down its advantages and disadvantages.
Answer:
Wind energy:

• It can converted into mechanical and electrical energy.
• Kinetic energy of the wind is used for running windmills, which can be used to lift water, grind grains, etc.

Advantages:

• Eco friendly
• Renewable

Disadvantages:

• Wind speed not uniform always.
• Needs a large area to erect series of windmills.
• Big amount of investment is needed.
• Output is less as compared to investment.

Extra Questions for Class 10 Science Chapter 14 Short Answer Type II

Question 1.
How can solar energy be harnessed? Mention any two limitations of using solar energy. Write down the advantages of solar cell.
Answer:
Solar energy:
Solar radiations can be converted into electricity through solar cells (photovoltaic cells). Photovoltaic cells convert solar radiations directly into electricity through silicon solar cells. Solar cells are arranged on large flat sheets to form a solar panel.

Advantages of solar cell:

• Solar cell have no moving parts, require little maintenance and work quite satisfactorily.
• They can be setup in remote and inaccessible hamlets or very sparsely inhabited areas.

Limitations:

• Solar cells are expensive.
• Solar devices are only useful during day time and on a sunny day.

Question 2.
Write two different ways of harnessing energy from the ocean.
Answer:
Energy from the sea:
1. Tidal energy: Locations in India – Gulf of Kutch, Gujarat and West Bengal

• Depends upon harnessing the rise and fall of sea level due to tidal action.
• Dams are constructed across a narrow part of sea the and a turbine converts tidal energy into electrical energy.

Disadvantage: Uniform tidal action is not seen.

2. Wave energy:

• Kinetic energy of the sea waves are used to rotate turbines.
• These turbines generate electrical energy.

Question 3.
Write a short note on geothermal energy.
Answer:

• Energy harnessed from the heat of the Earth is called geothermal energy.
• Magma is formed when this heat melts the rocks. The molten rocks and hot gases are called magma.
• The magma gets collected at some depths below the earth’s surface. These places are called “hot spots’.
• When underground water comes in contact with these hot spots, it changes into steam, which can be used to generate electricity.

Advantages of geothermal energy:

• Renewable.
• Cost of production is not much.

Disadvantages of geothermal energy:

• Only few sites available for harnessing energy.
• Expensive to set up.

Extra Questions for Class 10 Science Chapter 14 Long Answer Type

Question 1.
What is biomass? Explain the principle and working of a biogas plant using a labelled schematic diagram. Write down its advantages.
Answer:
Biomass is a source of conventionally used fuels that are used in our country, e.g., cow dung cakes, fire-wood, coal, charcoal.

Biogas: It is a mixture of gases produced during the decomposition of biomass in the absence of oxygen.
Methane is the major component of biogas. (Biogas contains 75% methane, carbon dioxide, hydrogen and hydrogen sulfide).

Biogas plant: Animal dung, sewage, crop residues, vegetable wastes, poultry droppings, etc. are used to produce biogas in biogas plants.

Construction and working:
The plant has a dome-like structure built with bricks. A slurry of cow dung and water is made in the mixing tank from where it is fed into the digester. The digester is a sealed chamber in which there is no oxygen. Anaerobic microorganisms, that do not require oxygen, decompose or breakdown complex compound of cow dung slurry and produce methane, carbon dioxide, hydrogen and hydrogen sulfide.

Advantages of biogas

• It bums without smoke and leaves no residue.
• Its heating capacity is high.
• The slurry of biogas plant is used as an excellent manure, rich in nitrogen and phosphorus.

Question 2.
Write down construction, advantages and limitations of a solar cooker.
Answer:
Solar cooker:
Construction:
Outer surface of the solar cooker is painted with black colour and a glass plate is used as cover.
Black colour absorbs more heat and the glass plate traps solar radiation by greenhouse effect. Mirror reflects the light.

Advantages of solar cookers

• Eco friendly
• Renewable
• Used in rural areas.
• Retains all the nutrients in food due to slow cooking.

Disadvantages of solar cooker

• Silicon cells are expensive.
• Solar radiations are not uniform over the Earth’s surface.
• Cannot be used at night or on cloudy days.
• Cannot be used to make chapattis for frying as these require a temperature of 140°C or more. (Maximum temperature of 100°C only can be achieved in a solar cooker.)

Question 3.
What is hydroelectric power plant? Write down its advantages and disadvantages.
Answer:
Hydroelectric power plant: A conventional renewable source of energy is obtained from water falling from a great height. Dams are constructed to collect water flowing in high altitude rivers. The stored water has a lot of potential energy. When water is allowed to fall from a height, potential energy changes to kinetic energy, which rotates the turbines to produce electricity.

Advantages:

• It is clean and non polluting source of energy.
• Hydropower is renewable source of energy.

Disadvantages:

• Highly expensive to construct.
• Dams cannot be constructed on all river sites.
• Large areas of human habitation and agricultural fields get submerged.
  People face social and environmental problems.

Sources of Energy HOTS Questions With Answers

Question 1.
What is the role of a plane mirror and a glass sheet in a solar cooker?
Answer:
Plane mirror reflects sunlight so that maximum sunlight can enter the box.
Glass sheet traps solar radiation by greenhouse effect.

Question 2.
What kind of mirror is used in concentrating type-solar cooker?
Answer:
A concave mirror is used in concentrating type solar cooker so that maximum heat can be concentrated at a given point.

Question 3.
Name the process that produces a large amount of energy in the sun.
Answer:
Nuclear fusion

Question 4.
Name the materials used for making solar cells.
Answer:
Silicon, Germanium and Selenium

Extra Questions for Class 10 Science Chapter 14 Value Based Questions

Question 1.
A. Reddy visited his grandfather’s village Koodankular with his younger sister. They saw people protesting against building a nuclear power plant there. Reddy’s sister asked the reason for the protests. Reddy said that it could be due to the risks involved in setting up the plant near people’s habitation.
(i) Write down the advantages and disadvantages of a nuclear power plant. ‘
(ii) Values shown by A. Reddy.
(iii) Which process is used to harness nuclear energy? Explain briefly.
Answer:
(i) Advantages of Nuclear energy:

• Alternative source of energy due to depletion of fossil fuels.
• From a small amount of fuel, a large amount of energy is released.

Disadvantages of Nuclear energy:

• Hazardous nature of nuclear waste and risk of nuclear waste leakage.
• High cost of setting up a nuclear plant.
• Displacement of people from their habitat.

(ii) A. Reddy is a very intelligent person.

(iii) Nuclear energy is produced by a process called nuclear fission. During this process, the nucleus of a heavy atom (such as uranium, plutonium or thorium) when bombarded with low-energy neutrons, can be split apart into lighter nuclei. The process releases a tremendous amount of heat energy. The released energy can be used to produce steam which is used to produce electricity.

Question 2.
During summer vacations Bhaskar visited his uncle’s village. He saw a biogas plant installed by villagers for their basic energy needs.
(i) What is biogas and biogas plant?
(ii) What values are shown by villagers?
Answer:
(i) Biogas: It is a mixture of gases produced during decomposition of biomass in the absence of oxygen. Methane is the major component of biogas.
Biogas plants: Animal dung, sewage, crop residues, vegetable wastes and, poultry droppings are used to produce biogas in biogas plants.

(ii) Villagers are intelligent and care for the environment.

Question 3.
Iatin aggarwal took admission in DTO (Delhi Technological University). He saw solar devices were installed in the university.
(i) Write down a short note on solar energy and solar cooker.
(ii) Write down the values shown by the university management.
Answer:
(i) (a) Solar energy:

• Solar radiations can be converted to electricity through solar cells (photovoltaic cells).
• Photovoltaic cells convert solar radiations directly into electricity through silicon solar cells.
• Solar cells arranged on a large flat sheet to form a solar panel.

(b) Solar cooker:
Solar cookers are painted black from outside and covered with a large glass plate to trap solar radiations by greenhouse effect.

(ii) University management is concerned about energy conservation.

In this page, we are providing Magnetic Effects of Electric Current Class 10 Extra Questions and Answers Science Chapter 13 pdf download. NCERT Extra Questions for Class 10 Science Chapter 13 Magnetic Effects of Electric Current with Answers will help to score more marks in your CBSE Board Exams.

Class 10 Science Chapter 13 Extra Questions and Answers Magnetic Effects of Electric Current

Extra Questions for Class 10 Science Chapter 13 Magnetic Effects of Electric Current with Answers Solutions

Extra Questions for Class 10 Science Chapter 13 Very Short Answer Type

Question 1.
Define magnetic effect of electric current.
Answer:
The production of magnetic field around a conductor when electric current is passed through it.

Question 2.
What is fuse?
Answer:
Fuse is the most important safety device, used for protecting the circuits due to short-circuiting or overloading of the circuits.

Question 3.
What is the pattern of magnetic field around a current carrying conductor?
Answer:
The magnetic field around a current carrying conductors forms a pattern of concentric circles.

Question 4.
Draw an appropriate schematic diagram showing common domestic circuits and discuss the importance of fuse.
Answer:

Extra Questions for Class 10 Science Chapter 13 Short Answer Type

Question 1.
What is electric motor? Write down its principle of working.
Answer:
Electric motor: An electric motor is a rotating device that converts electrical energy to mechanical energy.
Principle: A current-carrying conductor when placed in a magnetic field experiences a force.

Question 2.
What is galvanometer?
Answer:
A galvanometer is an instrument that can detect the presence of a current in a circuit.
The pointer remains at zero (the centre of the scale) for zero current flowing through it.
It can deflect either to the left or to the right of the zero mark depending on the direction of current.

Question 3.
Describe domestic electric circuits.
Domestic Electric circuits: In our houses, we receive AC electric power of 220 V with a frequency of 50 Hz. One of the wires in this supply is with red insulation, called live wire. The other one is of black insulation, which is a neutral wire. The potential difference between the two is 220 V.

The third is the earth wire that has green insulation and this is connected to a metallic body deep inside the earth. It is used as a safety measure to ensure that any leakage of current to a metallic body of an appliance does not give any severe shock to the user.

Question 4.
What will happen if a current carrying conductor is placed in magnetic field? How can the direction of magnetic field be found out?
Answer:
A current-carrying conductor when placed in a magnetic field experiences a force.
If the direction of the field and that of the current are mutually perpendicular to each other, then the force acting on the conductor will be perpendicular to both as given by Fleming’s left-hand rule.

Question 5.
What does the direction of thumb indicate in the right-hand thumb rule? In what ways this rule is different from Fleming’s left-hand rule?
Answer:
The thumb indicates the direction of current in the straight conductor held by curled fingers, whereas Fleming’s left-hand rule gives the direction of force experienced by current carrying conductor placed in an external magnetic field.

Question 6.
What is the difference between a direct current and an alternating current? How many times does AC used in India change direction in one second?
Answer:
Direct current always flows in one direction but the alternating current reverses its direction periodically. The frequency of AC in India is 50 Hz and in each cycle it alters direction twice. Therefore, AC changes direction 2 × 50 = 100 times in one second.

Question 7.
What is the role of fuse, used in series with any electrical appliance? Why should a fuse with defined rating not be replaced by one with larger rating?
Answer:
Fuse is used for protecting appliances due to short-circuiting or overloading. The fuse is rated for a certain maximum current and blows off when a current more than the rated value flows through it. If a fuse is replaced by one with larger ratings, the appliances may get damaged while the protecting fuse does not burn off. This practice of using fuse of improper rating should always be avoided.

Question 8.
On which factors does the magnetic field produced by a current carrying conductor at a given point depend?
Answer:
The magnetic field produced by a given current decreases as the distance from it increases.
The magnitude of the magnetic field produced at a given point increases as the current through the wire increases.

Question 9.
What is electric generator? Write down its principle of working.
Answer:
Electric Generator: A generator converts mechanical energy into electrical energy.
Principle: It works on the basis of electromagnetic induction. AC generator produces AC current and DC generator produces DC current.

Question 10.
What is difference between AC and DC? Write down advantage of AC over DC?
Answer:
The difference between the direct and alternating currents is that the direct current always flows in one direction, whereas the alternating current reverses its direction periodically.

In India, the AC changes direction after every 1/100 second, that is, the frequency of AC is 50 Hz. An important advantage of AC over DC is that electric power can be transmitted over long distances without much loss of energy.

Question 11.
With the help of a labelled circuit diagram illustrate the pattern of field lines of the magnetic field around a current carrying straight long conducting wire. How is the right hand thumb rule useful to find direction of magnetic field associated with a current carrying conductor?
Answer:
Right hand thumb rule states that if a current carrying straight conductor is held in the right hand with the thumb pointing towards the direction of current, then the fingers will wrap around the conductor in the direction of the field lines of the magnetic field.

Question 12.
Describe the activity that shows that a current-carrying conductor experiences a force perpendicular to its length and the external magnetic field. How does Fleming’s left-hand rule help us to find the direction of the force acting on the current carrying conductor?
Answer:

• Take a small aluminium rod AB (of about 5 cm). Using two connecting wires, suspend it horizontally from a stand.
• Place a strong horse-shoe magnet in such a way that the rod lies between the two poles with the magnetic field directed upwards. For this put the north pole of the magnet vertically below and south pole vertically above the aluminium rod.
• Connect the aluminium rod in series with a battery, a key and a rheostat.
• Now pass a current through the aluminium rod from end B to end A.
• It is observed that the rod is displaced towards the left. You will notice that the rod gets displaced.
• Reverse the direction of current flowing through the rod and observe the direction of its displacement. It is now towards the right.

The displacement of the rod in the above activity suggests that a force is exerted on the current-carrying aluminium rod when it is placed in a magnetic field. According to Fleming’s left hand rule stretch the thumb, forefinger and central finger of your left hand such that they are mutually perpendicular.

If the forefinger points in the direction of magnetic field and the central in the direction of current, then the thumb will point in the direction of motion or force acting on the conductor.

Extra Questions for Class 10 Science Chapter 13 Long Answer Type

Question 1.
Write down a short note on magnetic field produced by a solenoid.
Answer:
Magnetic field due to a solenoid
Solenoid: A coil of many circular turns of insulated copper wire wrapped closely in the shape of a cylinder is called a solenoid.

• The pattern of the magnetic field around a current carrying solenoid is same as that of a bar magnet. One end of the solenoid behaves as a magnetic North pole, while the other behaves as a South pole.
• The field lines inside the solenoid are in the form of parallel straight lines.
• The field is uniform inside the solenoid.
• A strong magnetic field produced inside a solenoid can be used to magnetise a piece of magnetic material, like soft iron, when placed inside the coil. The magnet so formed is called an electromagnet.

Field lines of the magnetic field through and around a current carrying solenoid

A current-carrying solenoid coil is used to magnetise steel rod inside it-an electromagnet

Question 2.
Describe the magnetic field produced due to current-carrying circular loop.
Magnetic field due to current-carrying circular loop
Answer:

• At the centre of the current carrying loop the magnetic field appears to be a straight line.
• The magnetic field produced by a current carrying wire at a given point depends directly on current passing through it.

Magnetic field lines of the field produced by a current-carrying circular loop

Question 3.
Define electromagnetic induction. Explain the ways by which magnetic field linked through a coil can be changed.
Answer:
Electromagnetic Induction: The phenomenon of electromagnetic induction is the production of induced current in a coil placed in a region where the magnetic field changes with time.

1. The magnetic field may change due to relative motion between the coil and the magnet.

Moving a magnet towards a coil sets up a current in the coil circuit, as indicated by deflection in the galvanometer needle

2. If the coil is placed near a current carrying conductor, the magnetic field may change either due to change in the current through the conductor or due to the relative motion between the coil and the conductor.

current is included in coil – 2 when current in coil – 1 changed

Question 4.
Define magnetic field and magnetic field lines. Write down the properties of magnetic field lines.
Answer:
Magnetic field:
The region surrounding a magnet, in which the force of the magnet can be detected, is said to have a magnetic field.

Magnetic field lines:
Magnetic field lines are the imaginary lines drawn in a magnetic field along which a north magnetic pole would move.

Properties of magnetic field line:

• Magnetic field lines are closed curves.
• The relative strength of the magnetic field is shown by degree of closeness of the field lines.
• No two field lines can cross each other as at the point of intersection the compass needle would point towards two directions, which is not possible.

Magnetic Effects of Electric Current HOTS Questions With Answers

Question 1.
AB is a current carrying conductor in the plane of the paper as shown in the Figure. What are the directions of magnetic fields produced by it at points P and Q? Given r₁ > r₂, where will the strength of the magnetic field be larger?
Answer:
Into the plane of paper at P and out of it at Q. The strength of the magnetic field is larger at the point located closer i.e., at Q.

Question 2.
Under what conditions permanent electromagnet is obtained if a current carrying solenoid is used? Support your answer with the help of a labelled circuit diagram.  [NCERT Exemplar]
Answer:

1. The current through the solenoid should be direct current.
2. The rod inside is made of a magnetic material such as steel.

Question 3.
A magnetic compass shows a deflection when placed near a current carrying wire. How will the deflection of the compass get affected if the current in the wire is increased? Support your answer with a reason.
Answer:
The deflection increases. The strength of magnetic field is directly proportional to the magnitude of current passing through the straight conductor.

Question 4.
It is established that an electric current through a metallic conductor produces a magnetic field around it. Is there a similar magnetic field produced around a thin beam of moving (i) alpha particles, (ii) neutrons? Justify your answer.
Answer:
(i) Yes, Alpha particles being positively charged constitute a current in the direction of motion.
(ii) No, the neutrons being electrically neutral does not constitute any current.

Question 5.
Why does a magnetic compass needle pointing North and South in the absence of a nearby magnet get deflected when a bar magnet or a current carrying loop is brought near it. Describe some salient features of magnetic lines of field concept.
Answer:
Current carrying loops behave like bar magnets and both have their associated lines of field. This modifies the already existing earth’s magnetic field and a deflection results. Magnetic field has both direction and magnitude. Magnetic field lines emerge from N – pole and enter S – pole. The magnetic field strength is represented diagrammatically by the degree of closeness of the field lines.

Field lines cannot cross each other as two values of net field at a single point cannot exist. Only one value, a unique net value, can exist. If in a given region, lines of field are shown to be parallel and equispaced, the field is understood to be uniform.

Extra Questions for Class 10 Science Chapter 13 Value Based Questions

Question 1.
Ravi took his grandma for MRI test. His younger sister asked some questions and Ravi answered?
(i) What is basic concept behind MRI?
(ii) Write down values shown by Ravi.
Answer:
(i) MRI or Magnetic Resonance Imaging is based on magnetic effect of electric current.
(ii) Ravi is a knowledgeble and caring too.