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MCQ Questions for Class 12 Biology Chapter 10 Microbes in Human Welfare

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Microbes in Human Welfare Class 12 MCQ Questions With Answers

Microbes In Human Welfare MCQ Class 12 Question 1.

Which gases are produced in anaerobic sludge digesters?

(A) Methane and CO2 only
(B) Methane, hydrogen sulphide and CO2
(C) Methane, hydrogen sulphide and O2
(D) Hydrogen Sulphide and CO2
Answer:
(B) Methane, hydrogen sulphide and CO2

Explanation :
In anaerobic sludge digesters, bacteria produce a mixture of gases like methane, hydrogen sulphide and CO2.

MCQ Questions for Class 12 Biology Chapter 10 Microbes in Human Welfare

Microbes In Human Welfare Class 12 MCQ Question 2.

Which of the following is used as clotbuster for removing clots from blood vessels of patients who have undergone myocardial infarction?

(A) Cyclosporin
(B) Statins
(C) Streptokinase
(D) Lipase
Answer:
(C) Streptokinase

Explanation :
Streptokinase produced by the bacterium Streptococcus and modified by genetic engineering is used as clotbuster.

Microbes In Human Welfare Class 12 MCQ Questions Question 3.

Conversion of milk to curd improves its nutritional value by increasing the amount of:

(A) Vitamin D
(B) Vitamin E
(C) Vitamin B12
(D) Vitamin A
Answer:
(C) Vitamin B12
Explanation :
Lactic acid bacteria (LAB) grow in milk and convert it to curd thereby improv-ing its nutritional quality bv increasing vitamin B12.

MCQ On Microbes In Human Welfare Class 12 Question 4.

Wastewater treatment generates a large quantity of sludge, which can be treated by

(A) digesters
(B) activated sludge
(C) chemicals
(D) oxidation pond
Answer:
(A) digesters

Explanation:
Sludge is a thick, soft and muddy deposits which can be treated by anaerobic digesters. Anaerobic digesters are large heated tanks in which microorganisms break down biodegradable material in the absence of oxygen. It is then sent to oxidation ponds where heterotrophic bacteria continue the breakdown of the organics and solar ultraviolet (UV) light destroys die harmful bacteria. Chemicals are not used in this treatment.

MCQ Questions for Class 12 Biology Chapter 10 Microbes in Human Welfare

Microbes In Human Welfare MCQ With Answers Question 5.

Methanogenic bacteria are not found in

(A) rumen of cattle
(B) gobar gas plant
(C) bottom of water-logged paddy fields
(D) activated sludge
Answer:
(D) activated sludge

Explanation : Methanogenic bacteria are an-aerobic microorganisms that grow in the presence of carbon dioxide and produce methane gas. These bacteria are not found in activated sludge. The microbes present in the activated sludge are aerobic bacteria that grow rapidly and form floes.

MCQ On Microbes In Human Welfare Class 12 Question 6.

BOD of wastewater is estimated by measuring the amount of

(A) total organic matter
(B) biodegradable organic matter
(C) oxygen evolution
(D) oxygen consumption
Answer:
(D) oxygen consumption

Explanation :
Biochemical oxygen demand (BOD) is estimated by measuring the amount of oxygen consumption or is a measure of the organic pollution of water. It refers lo the amount of dissolved oxygen required to decompose the organic matter in waste water high BOD indicates heavy pollution with little oxygen remaining for fish.

MCQ Questions for Class 12 Biology Chapter 10 Microbes in Human Welfare

Microbes In Human Welfare MCQ Questions Class 12 Question 7.

Big holes in Swiss cheese are made by

(A) a machine
(B) a bacterium that produces methane gas
(C) a bacterium producing a large amount of carbon dioxide
(D) a fungus that releases a lot of gases during its metabolic activities
Answer:
(C) a bacterium producing a large amount of carbon dioxide

Explanation :
he large holes in ‘Swiss cheese’ are made due to production of a large amount of CO2 by Propionibacterium sharmanii. It releases carbon dioxide when it consumes the lactic acid and forms bubbles. These bubbles form lilLle air pockets, resulting in the holes of the Swiss cheese.

Class 12 Biology Chapter 10 MCQ Question 8.

The primary treatment of waste water involves the removal of

(A) dissolved impurities
(B) stable particles
(C) toxic substances
(D) harmful bacteria
Answer:
(B) stable particles

Explanation :
The primary treatment of waste water involves the physical removal of both larger and smaller particles (stable particles) from the sewage with the help of filtration and sedimentation. These removals occur in the following stages: (i) Initially, floating debris is removed by sequential filtration, (ii) After that grit (made of soil and small pebbles) are removed bv sedimentation. All these solids it particles that settled form the primary sludge and the supernatant forms the effluent. The effluent is taken for the secondary treatment. ( The primary treatment does not remove the dissolved impurities, toxic substances and harmful bacteria.

Microbes In Human Welfare MCQs Class 12 Question 9.

The technology of biogas production from cow dung was developed in India largely due to the efforts of

(A) Gas Authority of India
(B) Oil and Natural Gas Commission
(C) Indian Agricultural Research Institute and Khadi and Village Industries Commission
(D) Indian Oil Corporation
Answer:
(C) Indian Agricultural Research Institute and Khadi and Village Industries Commission

Explanation :
Biogas (commonly called gobar gas) is produced by using cattle dung. The technology of biogas production from cowdung was developed in India mainly due to the efforts of Indian Agricultural Research Institute (LARI) and Khadi and Village Industries Commission (KVIC).

MCQ Questions for Class 12 Biology Chapter 10 Microbes in Human Welfare

MCQ Of Chapter 10 Biology Class 12 Question 10.

What would happen if oxygen availability to activated sludge floes is reduced?

(A) It will slow down the rate of degradation of organic matter.
(B) The centre of floes will become anoxic, which would cause death of bacteria and eventually breakage of floes.
(C) Floes would increase in size as anaerobic bacteria would grow around floes.
(D) Protozoa would grow in large numbers.
Answer:
(B) The centre of floes will become anoxic, which would cause death of bacteria and eventually breakage of floes.

Explanation :
Activated sludge microorganisms need oxygen as they oxidise wastes to obtain energy for growth. Insufficient oxygen will slow down or kill off aerobic micro-organisms, make facultative organisms work less efficiently and ultimately lead to the breakage of floes. It will also result in the production of the foulsmelling byproducts of anaerobic decomposition. So, sufficient oxygen must always be sustained in the aeration tank to ensure complete waste stabilisation.

MCQs On Microbes In Human Welfare Class 12 Question 11.

Which one of the following microbes forms symbiotic association with plants and help them in their nutrition?

(A) Axotobacter
(B) Aspetgillus
(C) Glomus
(D) Trichodema
Answer:
(C) Glomus

Explanation :
Glomus is a genus of arbuscular mycorrihizal fungi and, all species form symbiotic relationships with plant roots. They help the plant in the absorption of nutrients, especially phosphorus from soil.

Class 12 Biology Microbes In Human Welfare MCQ Question 12.

A nitrogen-fixing microbe associated with Azolla in rice fields is:

(A) Spirulina
(B) Ambaena
(C) Frankia
(D) Tolypothrix
Answer:
(B) Ambani

Explanation:
The fern, Azolla and the blue-green alga Anabaena azollae maintain a symbiotic relationship. The alga provides nitrogen to the fern, and the fern provides a habitat for the alga. This property of nitrogen fixation has made Azolla extremely important economically in the cultivation of rice.

Microbes In Human Welfare MCQs Pdf Class 12 Question 13.

Which one of the following is an example of carrying out biological control of pests/diseases using microbes?

(A) Trichoderma sp. against certain plant pathogens
(B) Nucleoplyhedrovirus against white rust in Brassica.
(C) Bt-cotton to increase cotton field.
(D) Ladybird beetle against aphids in mustard.
Answer:
(C) Bt-cotton to increase cotton field.

Explanation :
Bl-cotton is genetically modified organism cotton variety, which produces an insecticide to bollworms. It increases yield of cotton due to effective control of three types of bollworms viz, American spoiled pink bollworms.

MCQ Questions for Class 12 Biology Chapter 10 Microbes in Human Welfare

MCQ Questions On Microbes In Human Welfare Question 14.

The free-living fungus Trichoderma can be used for

(A) killing insects
(B) biological control of plant disease
(C) controlling butterfly caterpillars
(D) producing antibiotics
Answer:
(B) biological control of plant disease

Explanation :
Trichoderma is a free-living fungus which is common in soil and root ecosystems. II is an effective biocontrol agent and used extensively for soilborne diseases. It has been also used successfully against many pathogenic fungi which belong to various genera, viz. Fusarium, Phytophthora and Scelerotia. It may suppress the growth of the disease-causing organisms in the rhizosphere through competition and thus reduce disease development. It produces antibiotics and toxins, such as trichothecenes and a sesquiterpene, and trichodermin, which have a direct effect on other organisms.

MCQs Of Biology Class 12 Chapter 10 Question 15.

Mycorrhiza does not help the host plant in

(A) enhancing its phosphorus uptake capacity.
(B) increasing its tolerance to drought.
(C) enhancing its resistance to root pathogens.
(D) increasing its resistance to insects.
Answer:
(D) increasing its resistance to insects.

Explanation :
Fungi form symbiotic association with the roots of higher plants called mycorrhiz.a (VAM), for example. Glomus. The fungal hyphac symbiont in these associations, absorb phosphorus from soil and passes it to the plant, Plants having such associations show other benefits also, such as resistance to root borne pathogens, tolerance to salinity and draught,and an overall increase in plant growth and development. Mycorrhiza does not help the host plant in increasing its resistance to insects.

MCQ Microbes In Human Welfare Class 12 Question 16.

Which one of the following is not a nitrogen-fixing organism?

(A) Anabaena
(B) Nostoc
(C) Azotobacter
(D) Pseudomonas
Answer:
(D) Pseudomonas

Explanation :
Pseudomonas is a denitrifying bacterium, which converts ammonia and nitrates into free nitrogen. These bacteria are responsible to release free nitrogen in the environment through nitrogen cycle. Anabaena, Nostoc and Azotobacter are niLrogen fixing organisms. Anabaena and Nostoc are types of cyanobacteria which are widely distributed in aquatic and terrestrial environments and can fix atmospheric nitrogen. Azotobacter is free-living bacteria, which absorb free nitrogen from soil, air and convert it into salts of nitrogen like amino acids and enrich soil nutrients.

12th Biology MCQ Questions Question 17.

Bacillus thuringiensis is widely used as :

(A) Insecticide
(B) Weedicides
(C) Rodenticide
(D) All of the above
Answer:
(A) Insecticide

Explanation :
Bacillus thuringiensis is to control butterfly caterpillar. These are available in sachets as dried spores which are mixed with water and sprayed on to vulnerable plants such as brassica and fruit trees, where these are eaten by the insect larvae. In the gut of the larvae, the toxin is released and the larvae get killed.

MCQ Questions for Class 12 Biology Chapter 10 Microbes in Human Welfare

Microbes MCQ Class 12 Chapter 10 Question 18.

Glomus form a symbiotic relationship with plant

(A) leaves
(B) stem
(C) root
(D) stem and root
Answer:
(C) root

Explanation :
Glomus, is a genus of arbuscular mvcorrhizal fungi and all species form a sym biotic relationship with plant roots. They help the plant in the absorption of nutrients, especially phosphorus from soil.

Microbes In Human Welfare MCQ Class 12 Question 19.

Which pigment gives a pinkish hue to rhizobium induced root nodules.

(A) Leghaemoglobin
(B) Carotenoid
(C) Mauveine
(D) None of the above
Answer:
(A) Leghaemoglobin

Explanation :
Leghaemoglobin is a haem protein with structural and functional similarities to animal myoglobin, is found uniquely in legume root nodules, the sites of
nitrogen fixation which form during symbiotic . association between legumes and soil bacteria I of the genus Rhizobium.

Question 20.

Match the items in Column ‘A’ and Column ‘B’ and choose correct answer.

            Column AColumn B
(a) Lady bird(i) Methanobacterium
(b) Mycorrhiza(ii) Trichoderma
(c) Biological control(iii) Aphids
(d) Biogas(Vi) Glomus

(A) a – (ii), b – (iv), c – (iii), d – (i)
(B) a – (iii), b – (iv), c – (ii), d – (i)
(C) a – (iv), b – (i), c – (ii), d – (iii)
(D) a – (iii), b – (ii), c – (i), d- – (iv)
Answer:
(B) a – (iii), b – (iv), c – (ii), d – (i)

Explanation:

Column AColumn BExplanation
(A)(iii)Ladybird is the very familiar beetle with red and black marking, used to get rid of Aphids.
(B)(iv)Fungi form symbiotic association, with the roots of higher plants called mycorrhiza (e.g. ] Glomus)
(C)(ii)Trichoderma is a fungus and used as a fungicide, it acts a biological control agent for the. treatment of plant disease.
(D)(i)Methanogens, particularly Methanobacterium, are found in cow dung. These bacteria! grow anaerobically on cellulosic material and produce large amount of methane along! with CO2 and H2.

Assertion and Reason Based MCQs

Directions: In the following questions a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as :
(A) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion
(B) Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A).
(C) Assertion (A) is true but reason (R) is false.
(D) Assertion (A) is false but reason (R) is true.

MCQ Questions for Class 12 Biology Chapter 10 Microbes in Human Welfare

Question 1.

Assertion (A): Bottled fruit juices bought from the market are clearer as compared to those made at home.
Reason (R): They are clarified by pectinases and proteases.

Answer:
(A) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion

Explanation :
The juice which is prepared at home is turbid, due to the presence of fibres, pectin, etc. The bottled fruit juices are clearer because they are clarified by pectinases and proteases.

Question 2.

Assertion (A): An inoculum of curd is used for curdling of milk.
Reason (R): It contains Lactobacillus, which improves nutritional quality by increasing Vitamin B12.

Answer:
(A) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion

Explanation :
The lactobacillus, produce acids which coagulate and partially digest the milk proteins. An inoculum of curd contains millions of LAB, which convert milk to curd.

Question 3.

Assertion (A): Statin is produced by a yeast called Trichoderma polysporum.
Reason (R): Its used lowers the blood cholesterol level in the body.

Answer:
(D) Assertion (A) is false but reason (R) is true.

Explanation :
Statin is produced by a yeast called Monascus purpureus It is a blood cholesterol-lowering agent.

Question 4.

Assertion (A): Methanogens do not produce oxygen.
Reason (R): Methanogens are obligate anaerobic micro-organisms.

Answer:
(A) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion

Explanation :
Methanogens are obligate anaerobic micro-organisms which do not produce oxygen. In the digesters (during secondary treatment of wastewater), heterotrophic microbes (methanogens) anaerobically digest bacteria and fungi in sludge producing mixture of gases such as methane, hydrogen sulphide and CO2 which form the biogas.

MCQ Questions for Class 12 Biology Chapter 10 Microbes in Human Welfare

Question 5.

Assertion (A): Activated sludge should have the ability to settle quickly.
Reason (R): To absorb pathogenic bacteria present in wastewater while sinking to the bottom of the settling tank.

Answer:
Option (C) is correct.

Explanation:
Activated sludge should have the ability to settle quickly so that it can be rapidly pumped back from sedimentation tank to aeration tank.

Question 6.

Assertion (A): Cyanobacteria increases the soil fertility and also add the organic matter to the soil.
Reason (R): They can fix free nitrogen in the atmosphere.

Answer:
(A) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion

Explanation :
Cyanobacteria are aulolrophic microbes that can fix almospheric nitrogen. They are also important biofertilizers that add organic matter to Lire soil.

Question 7.

Assertion (A): Members of the genus Glomus from mycorrhiza.
Reason (R): Mycorrhiza is an association of plants and fungi.

Answer:
(A) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion

Explanation :
Glomus is a genus of arbuscular mycorrhizal and form a symbiotic association with plants.

Question 8.

Assertion (A): Rhizobium leguminosarum is a symbiotic bacterium found in the root nodules of leguminous plants.
Reason (R): They have the ability to fix atmospheric nitrogen.

Answer:
(A) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion

Explanation :
Rhizobium leguminosarum is symbiotic bacterium that serves as a biofertilizers. These bacteria fix atmospheric nitrogen into organic forms, which is used by the plant as nutrient.

Question 9.

Assertion (A): Nucleopolyhedrovirus are useful as they are good biocontrol agents.
Reason (R): They are species-specific, narrow spectrum bioinsecticides.

Answer:
(A) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion

Explanation :
Nucleopolyhedrovirus is from the genus of baculoviruses. They are useful as they are good biocontrol agents. They are species-specific, narrow-spectrum bioinsecticides. They control only species-specific pests, do not affect non-target organisms beneficial insects are conserved they aid in problems no i negative impact on plants or other animals.

MCQ Questions for Class 12 Biology Chapter 10 Microbes in Human Welfare

Question 10.

Assertion (A): Blue-green algae are popular as bio-fertilisers.
Reason (R): Blue-green algae cause algal bloom in polluted water bodies.

Answer:
(D) Assertion (A) is false but reason (R) is true.

Explanation :
Bluegreen algae are not popular as biofertilisers, besides adding organic matter to the soil and increasing its fertility because they cause algal bloom in polluted water bodies and have copious mucilage that makes the fields slippery.

Case-Based MCQs

Attempt any four sub-parts from each question. Each sub-part carries 1 mark.

I. Read the following and answer any four questions from Q.1 to Q.5 given below:
Villagers in a place near Chambur started planning to make power supply for agricultural purpose from cow dung. They have started a biogas plant for the purpose. Study the flow chart for biogas production given below and answer the following questions.
Microbes In Human Welfare MCQ Class 12

Question 1.

Biogas is composed of majorly:

(A) methane, CO2 and O2
(B) CO2, H2S, and H
(C) methane, C02
(D) H2S, H and O2
Answer:
(C) methane, CO2

Explanation :
Biogas is composed of Methane (50-70%), CO2(30-40%) with traces of hydrogen sulphide and hydrogen.

Question 2.

In the given flow chart, ‘A’ denotes :

(A) aerobic bacteria
(B) methanogenic bacteria
(C) cellulose-degrading bacteria
(D) yeast and protozoa
Answer:
(B) methanogenic bacteria

Explanation :

The methanogenic bacteria are anaerobic organisms’ that convert CO2 to methane via a sequence of reactions.

Question 3.

What is represented by ‘B’ in the flow chart?

(A) Carbohydrates
(B) Protein polymers
(C) Organic adds
(D) Fat globules
Answer:
(C) Organic adds

Explanation :
In the second stage of bioga production, the simple soluble compounds or monomers are acted upon by fermentation causing microbes and converted into organic adds especially acetic add.

MCQ Questions for Class 12 Biology Chapter 10 Microbes in Human Welfare

Question 4.

‘C’ in the given flow chart represents:

(A) aerobic breakdown of complex organic compounds
(B) anaerobic digestion of complex organic compounds
(C) fermentation of organic compounds
(D) fermentation of monomers.
Answer:
(B) anaerobic digestion of complex organic compounds

Explanation :
‘C in the given flow chart rep-resents anaerobic digestion of complex organic compounds.

Question 5.

If ‘A’ is not added in the procedure

(A) methane will not be formed
(B) CO2 will not be formed
(C) organic compounds will not be converted to H2S
(D) O2 will not be formed
Answer:
(A) methane will not be formed
Explanation : If methanogenic bacteria is not added in the procedure methane formation will not take place.

II. Read the following text aind answer any four questions on the basis of the same :
Ecological Indicators: The presence of dragonflies can reveal changes in the water ecosystems more quickly than studying other animals or plants. In fact, from the nymph to the adult stage, the dragonfly has a significant, positive ecological impact. Dragonfly eggs are laid and hatched in or near water, so their lives show on impact on both water and land ecosystems. Once hatched, dragonfly nymphs can breathe in the air or underwater which enables them to eat mosquito larvae, other aquatic insects and worms, and even small aquatic vertebrates like tadpoles and small fish. Adult dragonflies capture and eat adult mosquitoes. Community wide mosquito control programs that spray insecticides to kill adult mosquitoes also kill dragonflies.

Question 1.

The approach to biological control includes :

(A) Import and release of an insect pest to a new area to provide hosts for natural enemies.
(B) Import and release of natural enemies from the native home of an alien insect pest that has invaded a new area.
(C) Preservation of natural enemies (predators & parasites) that are already established in an area.
(D) Use of insecticides to reduce alien insect pests to establish new equilibrium position.
Answer:
(A) Import and release of an insect pest to a new area to provide hosts for natural enemies.

Explanation :

The approach to biological control includes Preservation of natural encmies(prcdators & parasites) that are alii ready established in anarea.

Question 2.

Two diseases less likely to occur in a region with plenty of dragonflies are

(A) Yellow fever and amoebic dysentery
(B) Malaria and Yellow fever
(C) Anthrax and typhoid
(D) Cholera and typhoid
Answer:
(B) Malaria and Yellow fever

Explanation :
Two diseases less likely to occur in a region with plenty of dragonflies are Maaria and Yellow fever.

MCQ Questions for Class 12 Biology Chapter 10 Microbes in Human Welfare

Question 3.

Dragonflies indicate positive ecological impact as:

(A) The presence of dragonflies indicates polluted water.
(B) Dragonfly nymphs selectively eat mosquito larvae.
(C) They help to decrease the probability of diseases spread by vectors.
(D) Dragonfly do not cause any harm to beneficial species.
Answer:
(C) They help to decrease the probability of diseases spread by vectors.

Explanation :
Adult dragonflies arc beneficial because the eat pest, flying insects, particular Ivmidges and mosquitoes and help to decrease the probability of diseases spread bv vectors.

Question 4.

The most effective stages in the life cycle of dragonflies that eradicating mosquitoes area.

(A) Larvae and adult
(B) Caterpillar and adult
(C) Nymph and adult
(D) Pupa and adult
Answer:
(C) Nymph and adult

Explanation :
Dragonflies are large and heavybodied insects. The larvae (or Nymphs), which live in water, eat almost anything living that is smaller than themselves. The adult dragonfly larvae are even known to catch and eat small fish. Usually they eat bloodworms or other aquatic insect larvae. Dragonfly nymphs are such good hunters because they move really fastby what looks like jet propulsion. One of the benefits of having dragonflies live nearby is that they eat many times their weight in mosquitoes every day. Dragonflies also eat many different kinds of flies. Using a basketlike arrangement of their legs, adult drag onflies can actually catch and eat other bugs while they are flying.

Question 5.

Assertion: Releasing dragonflies in areas where there is an outbreak of malarial diseases can be an environment-friendly method of control.
Reason: Dragonflies are dominant species and will not allow mosquitoes to reproduce.

(A) Both assertion and reason are true, and the reason is the correct explanation of the assertion.
(B ) Both assertion and reason are true, but the reason is not the correct explanation of the assertion. .
(C) Assertion is true but reason is false.
(D) Both assertion and reason are false.
Answer:
(C) Assertion is true but reason is false.

Explanation :
Dragonflies have role in controlling the mosquitoes population and ultimately malarial disease as they are predators on them but they have no role to allow mosquitoes to reproduce.

III. Read the following text and answer the any four questions on the basis of the same:
Large quantities of sewage is generated every day in cities and towns, which is treated in Sewage Treatment Plants (STPs) to make it less polluted. Given below is the flow diagram of one of the stages of STP Observe the given flow diagram and answer the questions accordingly.

MCQ Questions for Class 12 Biology Chapter 10 Microbes in Human Welfare

Question 1.

Primary effluent is passed into large aeration tanks:

(A) To allow bacterial floes to settle down
(B) To allow fast growth of useful aerobic microbes into floes
(C) To allow anaerobic sludge digestion
(D) None of these
Answer:
(C) To allow anaerobic sludge digestion

Explanation :
The primary effluent is trans-ferred into large aeration tanks where it is constantly agitated mechanically and the air having oxygen is pumped into it which allows fast growth of useful aerobic microbes into floes (masses of bacteria associated with fungal filaments to form mesh-like structures).

Question 2.

Technical term used for sediment formed in sewage treatment is:

(A) Floes
(B) Effluents
(C) Activated sludge
(D) Anerobic sludge
Answer:
(B) Effluents

Explanation :
The effluent after primary treatment is passed into the settling tank where the bacterial ‘floes’ are allowed to settle down and this sediment is called Activated sludge. A small part of the activated sludge is pumped back into the aeration tank to serve as the inoculum(starter).

Question 3.

The significance of the above sediment formed is that:

(A) It acts as inoculum
(B) It serves in formation of floes
(C) It helps in formation of natural water bodies
(D) It helps in anerobic sludge digestion
Answer:
(A) It acts as inoculum

Explanation :
The activated sludge is pumped back into the aeration tank to serve as the inoculum(starter).

MCQ Questions for Class 12 Biology Chapter 10 Microbes in Human Welfare

Question 4.

Identify the correct set of gases produced during digestion of sludge:

(A) methane, hydrogen sulphide and carbon dioxide
(B) methane, sulphur and carbon dioxide
(C) carbon monooxide, methane, hydrogen sulphide
(D) methane, hydrogen sulphide and nitrogen

Answer:
(A) methane, hydrogen sulphide and carbon dioxide

Explanation :
During this digestion, bacteria produce a mixture of gases such as methane, hydrogen sulphide, and carbon dioxide. These gases form biogas and can be used as a source of energy. The treated effluent from the secondary treatment plant is generally released into natural water bodies like rivers and streams.

MCQ Questions for Class 12 Biology Chapter 10 Microbes in Human Welfare

Question 5.

The technology of biogas production from cow dung was developed in India largely due to the efforts of:

(A) Gas authority of India
(B) Oil and Natural Gas Commission
(C) Indian Agriculture Research Institute, Khadi and Village Industries Commission.
(D) Indian Oil Corporation
Answer:
(C) Indian Agriculture Research Institute, Khadi and Village Industries Commission.

MCQ Questions for Class 12 Biology with Answers

Memories of Childhood Class 12 MCQ Questions with Answers English Chapter 8

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Check the below NCERT MCQ Questions for Class 12 English Vistas Chapter 8 Memories of Childhood with Answers Pdf free download. MCQ Questions for Class 12 English with Answers were prepared based on the latest exam pattern. We have provided Memories of Childhood Class 12 English MCQs Questions with Answers to help students understand the concept very well. https://mcqquestions.guru/memories-of-childhood-class-12-mcq-questions/

MCQ Questions for Class 12 English Vistas Chapter 8 Memories of Childhood with Answers

Memories Of Childhood MCQ Chapter 8 Question 1.
Bama’s brother told her that if she wanted to make progress, she had to
(a) learn to cook
(b) study
(c) learn to stitch and knit
(d) learn to drive

Answer

Answer: (b) study

Memories Of Childhood Class 12 MCQ Question 2.
Bama was very rebellious and the thought of oppression at the hands of upper castes
(a) infuriated her
(b) provoked her to slap someone
(c) made her abusive
(d) made her want to murder someone

Answer

Answer: (a) infuriated her

MCQ Of Memories Of Childhood Class 12 Question 3.
Bama’s elder brother was studying at
(a) school
(b) college
(c) university
(d) medical college

Answer

Answer: (c) university

Memories Of Childhood MCQs Chapter 8 Question 4.
She had thought that the man carrying the bag was only
(a) making a game out of carrying the parcel
(b) trying to make her laugh
(c) obeying orders
(d) not touching it because it was hot

Answer

Answer: (a) making a game out of carrying the parcel

Memories Of Childhood MCQ Questions And Answers Question 5.
The man was carrying
(a) pakoras
(b) samosas
(c) jalebis
(d) vadai or green banana bhaji

Answer

Answer: (d) vadai or green banana bhaji

English MCQs Class 12th Chapter 8 Question 6.
One day the author was attracted by the sight of
(a) two riders on a horse
(b) a monkey performing tricks
(c) cattle treading out the grain from straw
(d) dogs fighting with cats

Answer

Answer: (c) cattle treading out the grain from straw

Question 7.
There would always be some kind of entertainment
(a) in the school
(b) in the church
(c) in the bazaar
(d) in the house

Answer

Answer: (c) in the bazaar

Question 8.
Bama used to dawdle along from school because she was
(a) too slow
(b) crippled
(c) distracted by lots of things on the way
(d) unable to wait for the school bus

Answer

Answer: (c) distracted by lots of things on the way

Question 9.
The author Bama felt she already had experienced the humiliation due to
(a) dark skin
(b) short height
(c) poverty
(d) untouchability

Answer

Answer: (d) untouchability

Question 10.
The author was being stared at by people and she felt she
(a) looked pretty
(b) looked terrible
(c) had suffered extreme indignities
(d) looked like a model

Answer

Answer: (c) had suffered extreme indignities

Question 11.
We have to submit because they are strong’. These words were said by
(a) Zitkala-Sa
(b) Judewin
(c) Marry-Ann
(d) Christine

Answer

Answer: (b) Judewin

Question 12.
Short hair, in the author’s tribe, was worn only by
(a) mourners
(b) old people
(c) young kids
(d) elderly women

Answer

Answer: (a) mourners

Question 13.
While others ate, the author
(a) laughed
(b) watched them
(c) cried
(d) frowned

Answer

Answer: (c) cried

Question 14.
Everyone kept standing except
(a) the teacher
(b) the matron
(c) the caretaker
(d) the author

Answer

Answer: (d) the author

Question 15.
As the bell rang, the whole group of pupils
(a) sat on the floor
(b) drew a chair from under the table
(c) sat on the stools
(d) knelt down on the ground

Answer

Answer: (b) drew a chair from under the table

Question 16.
The Indian girls wore
(a) clinging dresses
(b) nightgowns
(c) trousers
(d) skirts

Answer

Answer: (a) clinging dresses

Question 17.
Zitkala was being constantly observed by a woman who had
(a) a pale face
(b) fair complexion
(c) dark complexion
(d) angry look

Answer

Answer: (a) a pale face

Question 18.
Rama was a
(a) Bengali writer
(b) a Tamil Dalit
(c) an NRI
(d) a politician

Answer

Answer: (b) a Tamil Dalit

Question 19.
Zitkala-Sa was a victim of
(a) racial prejudice
(b) serious crime
(c) rape
(d) a car accident

Answer

Answer: (a) racial prejudice

Question 20.
The lesson ‘Memories of Childhood’ is
(a) an autobiographical episode
(b) a fable
(c) a legend
(d) a play

Answer

Answer: (a) an autobiographical episode

Question 21.
Which family did Bama belog to?
(a) A jewish family
(b) a rich family
(c) a poor catholic family
(d) all

Answer

Answer: (c) a poor catholic family

Question 22.
What was the name of the school where Zitkala studied?
(a) Carlisle Indian school
(b) Carlisle Western school
(c) Carlisle Indonesian school
(d) Carlisle American school

Answer

Answer: (a) Carlisle Indian school

Question 23.
What was the author’s original name?
(a) Zitkala
(b) Zitkala sa
(c) Zitkala Bama
(d) Gertrude Simmons Bonnin

Answer

Answer: (d) Gertrude Simmons Bonnin

Question 24.
Why did Zitkala hide herself?
(a) to save herself
(b) to save herself from a woman
(c) to save herself from other children
(d) to stop people from cutting her hair

Answer

Answer: (d) to stop people from cutting her hair

Question 25.
What was common between Bama and Zitkala?
(a) belonged to minority
(b) victims of cultural differences
(c) were struggling because of class
(d) all these

Answer

Answer: (d) all these

Question 26.
What sort of shows attracted Bama?
(a) shows by jugglers
(b) shows by monkeys
(c) shows by shopkeepers
(d) shows by political people

Answer

Answer: (d) shows by political people

Question 27.
What did Judewin tell Zitkala?
(a) A new dress is comming
(b) she will meet her mother
(c) she will go to a new place
(d) her hair would be cut

Answer

Answer: (d) her hair would be cut

Question 28.
Why did the Landlord’s man ask Bama’s brother on which street did they live?
(a) to know his class
(b) to know his background
(c) to know his work
(d) to know his caste

Answer

Answer: (d) to know his caste

Question 29.
Why did Zitkala feel oppressed in her new establishment?
(a) because of indignities shown to her
(b) because she didn’t like the place
(c) she wanted to be with her mother
(d) none

Answer

Answer: (a) because of indignities shown to her

Question 30.
Why did Zitkala find Eating by formula a hard trial?
(a) because of her inability to follow the bell taps
(b) because of too many rules
(c) because of restrictions
(d) none

Answer

Answer: (a) because of her inability to follow the bell taps

Question 31.
Which community does Bama belong to?
(a) rich
(b) Brahmins
(c) Untouchable low caste
(d) None

Answer

Answer: (c) Untouchable low caste

Question 32.
Who told Bama that untouchability is a crime?
(a) her mother
(b) Zitkala and Sa
(c) her sister
(d) Her brother Annan

Answer

Answer: (d) Her brother Annan

Question 33.
What did Zitkala mean by Eating By Formula?
(a) Set pattern of sitting
(b) set pattern of standing in lines
(c) set pattern of rules
(d) set pattern of eating decorum

Answer

Answer: (d) set pattern of eating decorum

Question 34.
What was Bama victim of?
(a) gender prejudice
(b) violence
(c) child abuse
(d) caste system

Answer

Answer: (d) caste system

Question 35.
Why did Bama reach home in one hour in place of 10 minutes?
(a) she was watching shows on the road
(b) she was stopping at every shop
(c) she was enjoying all fun on the roads
(d) all these

Answer

Answer: (d) all these

Question 36.
How much time did Bama take to reach home?
(a) 2 hours
(b) 3hours
(c) 4hours
(d) 1 hour

Answer

Answer: (d) 1 hour

Question 37.
What did the cutting of long hair of Zitkala Sa symbolise in the lesson?
(a) subjection to the rulers
(b) her wish to dominate
(c) her wish to get justice
(d) her wish to look modern

Answer

Answer: (a) subjection to the rulers

Question 38.
Who was Zitkala Sa?
(a) A tamilian
(b) A protester
(c) A native American
(d) None

Answer

Answer: (c) A native American

Question 39.
What are the names of the two women?
(a) Zitkala Sa a Native American and Bama Tamilian Dalit
(b) Zitkala and Sa
(c) Ba and Ma
(d) Annan and Bama

Answer

Answer: (a) Zitkala Sa a Native American and Bama Tamilian Dalit

Question 40.
Who is the author of the lesson Memories of childhood?
(a) Zitkala-Sa and Bama
(b) Emily Brontë
(c) Charles Dickens
(d) None

Answer

Answer: (a) Zitkala-Sa and Bama

Question 41.
What had hurt Bama in the society?
(a) Political plays
(b) class students
(c) Road shows
(d) Practice of untouchability

Answer

Answer: (d) Practice of untouchability

Question 42.
What is Belfry?
(a) part of a bell tower
(b) part of a tower
(c) part of a music tower
(d) part of a silver tower

Answer

Answer: (a) part of a bell tower

Question 43.
What did the story showcase?
(a) Discrimination on the basis of casteism specially with Indians in western culture
(b) difference of Indian and Western culture
(c) views of minorities
(d) none

Answer

Answer: (a) Discrimination on the basis of casteism specially with Indians in western culture

Question 44.
How did the scene in the market change Bama’s life?
(a) because of that she decided to study hard and stand against discrimination
(b) she became fearful
(c) she became stubborn
(d) she was irritated

Answer

Answer: (a) because of that she decided to study hard and stand against discrimination

Question 45.
Why did Zitkala start crying at the dining table ?
(a) she didn’t like the food
(b) she was a stranger
(c) because of eating by formula
(d) all these

Answer

Answer: (c) because of eating by formula

We hope the given NCERT MCQ Questions for Class 12 English Vistas Chapter 8 Memories of Childhood with Answers Pdf free download will help you. If you have any queries regarding CBSE Class 12 English Memories of Childhood MCQs Multiple Choice Questions with Answers, drop a comment below and we will get back to you soon.

MCQ Questions for Class 12 Biology Chapter 8 Human Health and Disease

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Human Health and Disease Class 12 MCQ Questions With Answers

Human Health And Disease MCQ Question 1.

The term ‘Health’ is defined in many ways. The most accurate definition of the health would be

(A) health is the state of body and mind in a balanced condition.
(B) health is the reflection of a smiling face.
(C) health is a state of complete physical, mental, and social well-being.
(D) health is the symbol of economic prosperity.
Answer:
(C) health is a state of complete physical, mental, and social well-being.

Explanation :
Health may be defined as a person’s mental and physical condition. It is a slate of complete physical, mental and social well-being and not merely the absence of disease or infirmity. When people are healthy, they are more efficient in their work. It also increases longevity of people and reduces infant and maternal mortality.

Human Health And Disease Class 12 MCQ Question 2.

The organisms which cause diseases in plants and animals are called

(A) pathogens.
(B) vectors.
(C) insects.
(D) worms.
Answer:
(A) pathogens.

Explanation :
Pathogens are diseases causing microorganisms, it may be bacteria, viruses, fungi, etc. Pathogen disrupts the normal physiology of a multicellular animal or plant. Vector is an organism that spreads disease or parasite from one animal to another.

MCQ Questions for Class 12 Biology Chapter 8 Human Health and Disease

MCQ On Human Health And Disease Class 12 Question 3.

When an apparently healthy person is diagnosed as unhealthy by a psychiatrist, the reason could be that

(A) the patient was not efficient at his work.
(B) the patient was not economically prosperous.
(C) the patient shows behavioral and social maladjustment.
(D) he does not take interest in sports.
Answer:
(C) the patient shows behavioral and social maladjustment.

Explanation:
Health is a state of complete physical, mental, and social wellbeing. So, when an apparently healthy person is diagnosed as unhealthy by a psychiatrist the reason could be that the patient shows behavioral and social maladjustment due to mental discomfort. If patient is not efficient at his/her work and does not show interest in routine, social, and sports activities it means that he is physically not well and needs treatment by a psychiatrist.

MCQ On Human Health And Disease Class 12 Question 4.

Diseases are broadly grouped into infectious and non-infectious diseases. In the list given below, identify the infectious diseases,

(i) Cancer
(ii) Influenza
(iii) Allergy
(iv) Small pox

(A) (i) and (ii)
(B) (ii) and (iii)
(C) (iii) and (iv)
(D) (ii) and (iv)
Answer:
(D) (ii) and (iv)

Explanation :
In the given list, influenza (ii) and smallpox (iv) are infectious diseases. Infectious diseases can be spread from one person to another, through contact with body fluids, by aerosols (through coughing and sneezing), or via a vector. Whereas cancer and allergy are non-communicable diseases and cannot spread from infected persons to healthy people.

MCQ Questions for Class 12 Biology Chapter 8 Human Health and Disease

Human Health And Disease MCQ Class 12 Question 5.

The chemical test that is used for diagnosis of typhoid is

(A) ELISA-Test
(B) ESR-Test
(C) PCR-Test
(D) Widal-Test
Answer:
(D) Widal-Test

Explanation :
Widal test is used to help make a presumptive diagnosis of enteric fever, also known as typhoid fever. Typhoid is caused by Salmonella typhi. It is spread through food, milk, and water contaminated with intestinal discharges either directly or through flies and personal hygiene. Enzyme-linked immuno-sorbent assay (ELISA) is used in immunology to detect the presence of an antibody or an antigen in a sample. Erythrocyte sedimenta-tion rate test (ESR) is used to detects inflammation that may be caused by infection and some autoimmune diseases. Polymerase chain reaction (PCR) test is used in molecular biology. It is used to make numerous copies of a specific segment of DNA quickly and accurately.

Class 12 Human Health And Disease MCQ Question 6.

One of the following is not the causal organism for ringworm.

(A) Microsporum
(B) Trichophyton
(C) Epidermophyton
(D) Microsporum
Answer:
(D) Microsporum

Explanation :
Ringworm infections are caused by fungi belonging to the genera Microsporum, Trichophyton, and Epidermophyton. Microsporum is an ectomycorrhizal zoosporic fungus causing diseases of economically important vascular plants.

Class 12 Biology Chapter 8 MCQ Question 7.

Which type of immune response is responsible for the rejection of tissues/organs in the patient’s body post-transplantation?

(A) auto-immune response
(B) humoral immune response
(C) physiological immune response
(D) cell-mediated immune response
Answer:
(D) cell-mediated immune response

Explanation :
The body is able Lo differentiate self and non-self and the cell-mediated immune response is responsible for the graft rejection.

MCQ Questions for Class 12 Biology Chapter 8 Human Health and Disease

MCQ Human Health And Disease Class 12 Question 8.

Which of the following toxic substance is responsible for the malarial fever.

(A) Haemocyanin
(B) Haemozoin
(C) Haemoglobin
(D) Haemoriden
Answer:
(B) Haemozoin

Explanation:
The rupture of RIlC’s is associated with release of a toxic substance, hemozoin, which is responsible for the chill and high fever recurring every three to four days.

Class 12 Biology Human Health And Disease MCQ Question 9.

Non-specific host defense that exists prior to the exposure of an antigen is called :

(A) acquired immunity
(B) passive immunity
(C) innate immunity
(D) active immunity
Answer:
(C) innate immunity

Explanation: Innate immunity is nonspecific type of defense, that is present at the time on birth.

MCQ Of Human Health And Disease Chapter 8 Question 10.

A person with sickle cell anemia is

(A) more prone to malaria.
(B) more prone to typhoid.
(C) less prone to malaria.
(D) less prone to typhoid.
Answer:
(C) less prone to malaria.

Explanation:
A person with sickle cell anemia is less prone to malaria because in sickle cell anemia red blood cells become abnormally shaped if they inherit two faulty copies of the gene for the oxygen-carrying protein hemoglobin. The faulty gene persists because even carrying one copy of it confers some resistance to malaria. Therefore, people with normal hemoglobin A are susceptible to death from malaria but people with sickle cell trait who have one gene for hemoglobin A and other for hemoglobin S have a greater chance of surviving malaria and do not suffer adverse consequences from the hemoglobin gene.

MCQ On Human Health And Diseases Pdf Class 12 Question 11.

Opium is obtained from:

(A) Papaver somniferum
(B) Cannabis sativa
(C) Erytkroxylum coca
(D) Datura metal
Answer:
(A) Papaver somniferum

Explanation :
Opium, narcotic drug that is obtained from the unripe seedpods of the opium poppy (Papaver somniferum).

MCQ Questions for Class 12 Biology Chapter 8 Human Health and Disease

Health And Disease Class 12 MCQ Question 12.

Synthetic drugs structurally related to adrenaline are

(A) hallucinogens
(B) Analgesics
(C) Amphetamines
(D) Barbiturates
Answer:
(C) Amphetamines

Explanation :
Amphetamines (stimulants) mimic the effect of the naturally produced hormone adrenaline.

MCQ Of Chapter 8 Biology Class 12 Question 13.

‘Smack’ is a drug obtained from the

(A) latex of Pa-paver somniferum.
(B) leaves of Cannabis sativa.
(C) flowers of Dhatura.
(D) fruits of Erythroxylum coca.
Answer:
(A) latex of Pa-paver somniferum.

Explanation :
Heroin, commonly called smack, is chemically diacetylmorphine. It is a white, odorless, bitter, crystalline compound which is obtained by acetylation of morphine, extracted from the latex of poppy plant (Papaver somniferous). Leaves of Cannabis sativa (commonly called bhang) produce cannabinoids. Dhatura flower produces tropane alkaloids (mainly sco polyamines, hyoscyamine and atropine). Atropine reduces salivation and bronchial secretions before surgery. It is also used to dilate the pupil before eye exams and to relieve pain which is caused by swelling and inflammation in the eye. Cocaine is extracted from the dried leaves and young twigs of Erythroxylum coca.

Human Health And Disease Class 12 MCQ Questions Question 14.

Tobacco consumption is known to stimulate secretion of adrenaline and nor-adrenaline. The component causing this could be

(A) nicotine
(B) tannic acid
(C) suramin
(D) catechin
Answer:
(A) nicotine

Explanation :
Nicotine is highly addictive and harmful for human health. Nicotiana tabacum, the type of nicotine is found in tobacco plants. Nicotine present in tobacco stimulates adrenal gland to release adrenaline and noradrenaline hormone which in turn increases the blood pressure and heart rate.

MCQ Questions for Class 12 Biology Chapter 8 Human Health and Disease

Chapter 8 Biology Class 12 MCQs Question 15.

The chronic intake of liver.

(A) opium
(B) alcohol
(C) cocaine
(D) tobacco
Answer:
(B) alcohol

Explanation :
Cirrhosis, which is a deadly liver disease caused due to excessive consumption of alcohol which damages the liver in such a way that is generally irreversible.

Human Health And Disease MCQ Questions Question 16.

Which one is correctly matched …

(A) Cocaine – Opiate narcotic
(B) Bhang – Analgesic
(C) Reserpine – Tranquilizer
(D) Morphine – Hallucinogen
Answer: Option (C) is correct.

Explanation :
Cocaine is a natural stimulant. It stimulates nervous system and delays fatigue. Bhang is a hallucinogen Morphine is a natural opiate derived from opium. Reserpine is a tranquiliser. It has sleep-inducing properties.

Human Health And Disease MCQs Class 12 Question 17.

Which compound is formed by acetylation of morphine?

(A) Heroin
(B) Cocaine
(C) Tobacco
(D) Marijuana
Answer:
(A) Heroin

Explanation:
Heroin is synthesized by acetylation of the two hydroxyl groups of morphine with acetyl chloride, hence its other names, diacetylmorphine or diamorphine.

Question 18.

Marijuana is extracted from

(A) dried leaves and flowers of hemp plant
(B) ergot fungus
(C) roots of hemp plant
(D) cocoa plant.
Answer:
(A) dried leaves and flowers of hemp plant

Explanation :
Marijuana is extracted from leaves and flowers of Cannabis sativa. is a CNS stimulant as it interferes with the transport of the neurotransmitter, dopamine.

MCQ Questions for Class 12 Biology Chapter 8 Human Health and Disease

(A) Valium
(B) Barbituarate
(C) Cocaine
(D) Opium
Answer:
(C) Cocaine

Explanation :
Cocaine attaches to the dopamine transporter and blocks the normal recycling process, resulting in a buildup of dopamine in the synapse, which contributes to the pleasurable effects of cocaine.

Question 20.

Which drug is used as medicine to help patients cope with depression and insomnia?

(A) Morphine
(B) Amphetamines
(C) Codeine
(D) LSD
Answer:
(B) Amphetamines

Explanation :
Amphetamines stimulate the nervous system, increase alertness and produce excitement.

Assertion and Reason Based MCQs

Directions: In the following questions a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as :

(A) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).
(B) Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A).
(C) Assertion (A) is true but reason (R) is false.
(D) Assertion (A) is false but reason (R) is true.

Question 1.

Assertion (A): Acquired immunity is pathogen specific.
Reason (R): It is not present since birth.

Answer:
(A) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).

Explanation :
Acquired immunity is learned, it is not present at birth.

MCQ Questions for Class 12 Biology Chapter 8 Human Health and Disease

Question 2.

Assertion (A): Sharing of injection needles between two individuals is not recommended.
Reason (R): This transmits STDs like AIDS and Hepatitis from the diseased person to the healthy person.

Answer:
(A) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).

Explanation :
Sharing of injection needles is not recommended so as to avoid the transmission of STDs like AIDS and Hepatitis from the diseased person to the health person.

Question 3.

Assertion (A): Pathogens are disease-causing organisms.
Reason (R): Salmonella typhi is a pathogenic virus causing tuberculosis.

Answer:
(C) Assertion (A) is true but reason (R) is false.

Explanation :
Salmonella typhi is a pathogenic bacterium that causes typhoid fever in human

Question 4.

Assertion(A): The colostrum provides passive immunity to the newborn baby.
Reason(R): In this, the readymade antibodies are directly given to protect the body.

Answer:
(A) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).

Explanation :
Colostrum (Mother’s first milk) contains good amount of antibodies like IgA , which provide passive immunity to the new born and protects it from various infections.

Question 5.

Assertion (A): Bone marrow and thymus are primary lymphoid organiser:
Reason(R): It is the organs, to which matured lymphocytes migrate, interact with antigens and then proliferate to become effector cells.

Answer:
(C) Assertion (A) is true but reason (R) is false.

Explanation :
Bone marrow and thymus are primary lymphoid organs as here immature lymphocytes differentiate into antigen-sensi-tive lymphocytes.

MCQ Questions for Class 12 Biology Chapter 8 Human Health and Disease

Question 6.

Assertion (A): Opioids, also called opiates used to treat pain.
Reason (R): Opioids are the drugs which kind to specific opioid receptors present in our central nervous system.

Answer:
(A) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).

Explanation :
When opioids bind to specific receptors present in our CNS, they block the pain messages sent from the body through the spinal cord to the brain.

Question 7.

Assertion (A): Heroin, the smack is chemically diacetylmorphine.
Reason (R): Heroin is obtained by acetylation of morphine.

Answer:
(A) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).

Explanation:
Reason is the correct explanation. of assertion. heroin is obtained by acetylation of morphine, which is extracted from the latex of the poppy plant.

Question 8.

Assertion (A): Cocaine are drug of abuse.
Reason (R): Cocaine interferes in The working of central nervous system.

Answer:
(C) Assertion (A) is true but reason (R) is false.

Explanation:
Cocaine interferes with the trans port of the neurotransmitter dopamine, which acts as chemical messenger in our body.

Question 9.

Assertion (A): Smoking increases the carbon monoxide (CO) content in the blood which has greater affinity to hemoglobin than oxygen.
Reason (R): CO forms a stable bond with hemoglobin and does not allow binding of oxygen. It reduces concentration of haem bound oxygen and causes oxygen deficiency in the body.

Answer:
(C) Assertion (A) is true but reason (R) is false.

Explanation :
Smoking increases the carbon monoxide (CO) content in the blood which has s greater affinity to haemoglobin than oxygen. (CO) forms a stable bond with haemoglobin and does not allow binding of oxygen. It reduces concentration of haem bound oxygen and causes oxygen deficiency in the body. Smok
ing also damages alveolar walls, which reduces respiratory surface (emphysema).

MCQ Questions for Class 12 Biology Chapter 8 Human Health and Disease

Question 10.

Assertion (A): Ganja is obtained from Cannabis sativa / hemp plant.
Reason (R): It is hallucinogenic, alters perception, causes illusion and damages cardiovascular system.

Answer:
(C) Assertion (A) is true but reason (R) is false.

Explanation:
Ganja is obtained from Cannabis sativa hemp plant. It is hallucinogenic, alters perception, causes illusion and damages cardiovascular system.

Case-Based MCQs

Attempt any four sub-parts from each question. Each sub-part carries 1 mark.

I. Read the following text and answer the following questions on the basis of the same :
Shivani studies in class I. Her parents come from a backward family and are unaware of immunization program. So, she did not get vaccinated properly. Once playing with her friends in the park, she fell down due to weakness and later complained of high fever, headache and stiffness in her neck.

Question 1.

The microbe responsible for Shivani’s illness may be:

(A) Vibrio cholerae
(B) Enterovirus
(C) Plasmodium
(D) Mycobacterium
Answer:
(A) Vibrio cholerae

Explanation:
The symptoms shown by Shivani suspects of having polio which is caused by a species of enterovirus.

Question 2.

Which vaccine if administered earlier, would have saved Shivani from the illness she contracted, unfortunately?

(A) MMR Vaccine
(B) Varicella Vaccine
(C) BCG Vaccine
(D) Salk Vaccine
Answer:
(D) Salk Vaccine

Explanation :
Salk Vaccine or inactivated poliovirus vaccine if administered earlier would have saved Shivani from contracting the disease.

Question 3.

The disease that Shivani has contracted spreads through:

(A) Mosquito bite
(B) Bite of infected dog
(C) Fecal oral route
(D) Direct contact of an infected person
Answer:
(C) Fecal oral route

Explanation: Poliovirus is contagious it spreads through stool of an infected person, droplets from sneeze, cough of infected person.

MCQ Questions for Class 12 Biology Chapter 8 Human Health and Disease

Question 4.

This type of infection produces inflammation in:

(A) Bones
(B) Liver
(C) Nervous System
(D) Heart
Answer:
(C) Nervous System

Explanation :
Polio produces inflammation in nervous system.

Question 5.

A step that can help to eradicate the disease Shivani has contracted is:

(A) Live Polio Vaccine
(B) Killed polio vaccine
(C) Combination of live and killed vaccines
(D) None of the above
Answer:
(C) Combination of live and killed vaccines

Explanation :
Combination of live and killed polio vaccines can help in eradication of polio a disease Shivani has contracted.

II. Read the following text and answer the following questions on the basis of the same:
Health is defined as a state of complete physical, mental and social well-being. Balanced diet, personal hygiene and regular exercise are very important to maintain good health. Any disturbance of structure or function of the body may be regarded as disease. Diseases can broadly be categorized into infectious (communicable) and non-infectious (non-communicable). A wide range of organisms belonging to bacteria, viruses, fungi, protozoans etc. could cause diseases in man.

Question 1.

Which of the following diseases are communicable?

(A) Infectious diseases
(B) Deficiency diseases
(C) Allergies
(D) Degenerative diseases.
Answer:
(A) Infectious diseases

Explanation:
Communicable, or infectious diseases, are caused by microorganisms such as bacteria, viruses, parasites and fungi that can be spread, directly or indirectly, from one person to another.

Question 2.

Which among the following is a set of bacterial diseases?

(A) Cholera, typhoid and mumps
(B) Malaria, mumps and poliomyelitis
(C) Diphtheria, leprosy and plague
(D) Tetanus, Tuberculosis and measles.
Answer:
(C) Diphtheria, leprosy and plague

Explanation :
Diphtheria is a serious bacterial infection that affects the mucous membranes of the throat and nose. Although it spreads easily from one person to another, diphtheria can be prevented through the use of vaccines. Leprosy is a chronic, progressive bacterial infection caused by the bacterium Mycobacterium leprae. It primarily affects the nerves of the extremities, the skin, the lining of the nose, and the upper respiratory tract. The plague is a serious bacterial infection that can be deadly. Sometimes referred to as the “black plague,” the disease is caused by a bacterial strain called Yersinia pestis. This bacterium is found in animals throughout the world and is usually transmitted to humans through fleas.

Question 3.

The nature of the spread of communicable diseases is known as.

(A) Parasitology
(B) Immunology
(C) Epidemiology
(D) None of these.
Answer:
(C) Epidemiology

Explanation :
Epidemiology deals with the occurrence, distribution and causes of diseases in mankind.

MCQ Questions for Class 12 Biology Chapter 8 Human Health and Disease

Question 4.

DPT vaccine is used for the immunization of :

(A) Cholera
(B) Bubonic plague
(C) Typhoid fever
(D) Whooping cough.
Answer:
(D) Whooping cough.

Explanation :
DTP vaccine can prevent diph-theria, tetanus, and pertussis. Diphtheria and pertussis spread from person to person. Tetanus enters the body through cuts or wounds. Diphtheria can lead to difficulty breathing, heart failure, paralysis, or death.

Directions: In the following questions a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as :

(A) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).
(B) Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A).
(C) Assertion (A) is true but reason (R) is false.
(D) Assertion (A) is false but reason (R) is true.

Question 5.

Assertion (A): Diphtheria is caused by Corynebacterium diphtheriae.
Reason (R): Corynebacterium diphtheriae produce a potent exotoxin that inhibits protein synthesis in epithelial cells.

Answer:
(A) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).

III. Read the passage and answer any four questions.
A group of youth were having a ‘rave party’ in an isolated area and was raided by police. Packets of ‘smack’ and syringes with needles were found littered around.

Question 1.

Why is taking ‘smack’ considered an abuse?

(A) because it causes drug dependence
(B) because it affects nervous system
(C) because it impairs one’s psychological functions
(D) all of these
Answer:
(D) all of these

Explanation :
An addictive substance causes drug dependence and affects nervous system. When used in more amounts or frequencies it impairs ones physical and psychological functions.

MCQ Questions for Class 12 Biology Chapter 8 Human Health and Disease

Question 2.

Which of the following drug is commonly known as Smack?

(A) Heroin
(B) Morphine
(C) Codeine
(D) Pethidine
Answer:
(A) Heroin

Explanation :
Heroin is commonly known as smack or brown sugar. It is a semisynthetic white crystalline powdery substance, which is chemically diacetylmorphine and is obtained by the acetylation of morphine.

Question 3.

‘Smack’ is a drug obtained from the

(A) Latex of Papaver somniferum
(B) Leaves of Cannabis sativa
(C) Flowers of Datura
(D) Fruits of Erythroxylum coca
Answer:
(A) Latex of Papaver somniferum

Explanation :
Latex of Paparer somniferum.

MCQ Questions for Class 12 Biology Chapter 8 Human Health and Disease

Question 4.

Syringes and needles used by the youth for taking the drug could prove to be very fatal as:

(A) They can acquire serious infections.
(B) They can lead to malnutrition.
(C) They can cause transmission of parasitic disease.
(D) They can lead to cardiac arrest.
Answer:
(A) They can acquire serious infections.

Explanation :
They can acquire serious infections transmission of HIV infections AIDS hepatitis.

MCQ Questions for Class 12 Biology Chapter 8 Human Health and Disease

Question 5.

When an healthy person is diagnosed as unhealthy by a psychiatrist, the reason could be that

(A) The patient was not efficient at his work.
(B) The patient was not economically prosperous.
(C) The patient shows behavioral and social maladjustment.
(D) The does not take interest in sports.
Answer:
(C) The patient shows behavioral and social maladjustment.

Explanation :
Health can be defined as a state of complete physical, mental and social well-being. So, when an apparently healthy person ” is diagnosed as unhealthy by a psychiatrist, the reason could be that the patient shows behavioral and social maladjustment. Due to mental discomfort.

MCQ Questions for Class 12 Biology with Answers

MCQ Questions for Class 12 Biology Chapter 7 Evolution with Answers

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Check the below NCERT MCQ Questions for Class 12 Biology Chapter 7 Evolution with Answers Pdf free download. MCQ Questions for Class 12 Biology with Answers were prepared based on the latest exam pattern. We have provided Evolution Class 12 Biology MCQs Questions with Answers to help students understand the concept very well. https://mcqquestions.guru/mcq-questions-for-class-12-biology-chapter-7/

Evolution Class 12 MCQs Questions with Answers

MCQ On Evolution Class 12 Pdf Chapter 7 Question 1.
Missing link in evolution is:
(a) Pheretima
(b) Limulus
(c) Peripatus
(d) Archaeopterys

Answer

Answer: (d) Archaeopterys

Evolution Class 12 MCQ Chapter 7 Question 2.
Hardy-Weinberg principle explains :
(a) Chromosomal
(b) Genetic drift
(c) Genetic equilibrium
(d) All of these

Answer

Answer: (c) Genetic equilibrium

Evolution MCQ Class 12 Chapter 7 Question 3.
As per Neo-Darwinism, which is mainly responsible for evolution?
(a) Mutation
(b) Natural drift
(c) Both of these
(d) All of these

Answer

Answer: (b) Natural drift

MCQ On Evolution Class 12 Chapter 7 Question 4.
Dispersal of population depends on:
(a) On immigration
(b) On Emigration
(c) On Migration
(d) All of these

Answer

Answer: (d) All of these

MCQs On Evolution Class 12 Chapter 7 Question 5.
Evolutionary history of an organism is known as:
(a) Ontogeny
(b) Phytogeny
(c) Ancestry
(d) Palaentolgy

Answer

Answer: (b) Phytogeny

Class 12 Biology Chapter 7 MCQ Question 6.
Book ‘Philosophique Zoologique’ was written by:
(a) Lamarck
(b) Mendel
(c) Darwin
(d) Hugo-devries

Answer

Answer: (a) Lamarck

MCQs Of Biology Class 12 Chapter 7 Question 7.
Which one of the following phenomenon supports Darwin’s concept of natural selection in organic evolution?
(a) Development of transgenic animals
(b) Production of‘Dolly the sheep’ by cloning
(c) Prevalence of pesticide resistant insects
(d) Development of organs from ‘Stem cells’ for organ transplantation

Answer

Answer: (c) Prevalence of pesticide resistant insects

MCQ Of Chapter 7 Biology Class 12 Question 8.
The biogenetic law of Haeckel is:
(a) Ominis vivum-e-eellula
(b) Omminis cellula-e-cellula
(c) Ontogeny repeats phytogeny
(d) Phytogeny repeats ontogeny

Answer

Answer: (c) Ontogeny repeats phytogeny

MCQ On Evolution Chapter 7 Class 12 Question 9.
Wings of Butterfly and birds are:
(a) Vestigial organs
(b) Analogous organs
(c) Homologous organs
(d) Both (a) and (b)

Answer

Answer: (b) Analogous organs

Question 10.
Theory of Pangenesis was given by:
(a) Darwin
(b) Lamarck
(c) Weismann
(d) DeVries

Answer

Answer: (a) Darwin

We hope the given NCERT MCQ Questions for Class 12 Biology Chapter 7 Evolution with Answers Pdf free download will help you. If you have any queries regarding Evolution CBSE Class 12 Biology MCQs Multiple Choice Questions with Answers, drop a comment below and we will get back to you soon.

MCQ Questions for Class 12 Physics Chapter 10 Wave Optics

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Wave Optics  Class 12 MCQs Questions with Answers

Wave Optics MCQ Physics Chapter 10 Class 12 Question 1.

Wavefront generated from a line source is

(A) cylindrical wavefront
(B) spherical wavefront
(C) plane wavefront
(D) either (A) or (B)
Answer:
(A) cylindrical wavefront

MCQ On Wave Optics Class 12 Chapter 10 Question 2.

Phase difference between any two points of a wavefront is

(A) π
(B) π/2
(C) 0
(D) π/4
Answer:
(C) 0

Explanation:
Wavefront is the locus of all points those are in same phase.

MCQ Questions for Class 12 Physics Chapter 10 Wave Optics

Wave Optics Class 12 MCQ Chapter 10 Question 3.

In Huygens theory, light waves

(A) are transverse waves and require a medium to travel.
(B) are longitudinal waves and require a medium to travel.
(C) are transverse waves and require no medium to travel.
(D) are longitudinal waves and require no medium to travel.
Answer:
(B) are longitudinal waves and require a medium to travel.

Explanation:
According to Huygens, light waves are longitudinal waves and require a material medium to travel. For this reason Huygens assumed the existence of a hypothetical medium called luminiferous ether.

MCQ Of Wave Optics Class 12 Chapter 10 Question 4.

Huygens theory could not explain

(A) photoelectric effect.
(B) reflection of light.
(C) diffraction of light.
(D) interference of light.
Answer:
(A) photoelectric effect.

Explanation:
Wave nature of light cannot explain the photoelectric effect. Particle nature of light can only explain it.

Wave Optics Class 12 MCQ Pdf Chapter 10 Question 5.

Which of the following statement is true?

(A) According to both Maxwell’s electromagnetic theory and Huygens wave theory light is treated as a wave in nature and require medium to travel.
(B) According to both Maxwell’s electromagnetic theory and Huygens wave theory light is treated as a particle in nature and require medium to travel.
(C) According to both Maxwell’s electromagnetic theory and Huygens wave theory light is treated as a wave in nature and does not require medium to travel.
(D) According to Maxwell’s electromagnetic theory light is treated as a wave in nature and require no medium to travel. According to Huygens theory light is treated as a wave in nature and require medium to travel.
Answer:
(D) According to Maxwell’s electromagnetic theory light is treated as a wave in nature and require no medium to travel. According to Huygens theory light is treated as a wave in nature and require medium to travel.

MCQ Questions for Class 12 Physics Chapter 10 Wave Optics

MCQ Wave Optics Class 12 Chapter 10 Question 6.

In a Young’s double-slit experiment the source is white light. One of the holes is covered by a red filter and another by a blue filter. In this case,

(A) there shall be alternate interference patterns of red and blue.
(B) there shall be an interference pattern for red distinct from that for blue.
(C) there shall be no interference fringes.
(D) there shall be an interference pattern for red mixing with one for blue.
Answer:
(C) there shall be no interference fringes.

Wave Optics MCQ Chapter 10 Class 12 Question 7.

Figure shows a standard two-slit arrangement with slits S1, S2. P1, P2 are the two minima points on either side of P shows in Figure. At P2 on the screen, there is a hole and behind P2 is a second screen, 2-slit arrangement with slits S3 and S4 and a second screen behind them.

Wave Optics MCQ Questions With Answers
(A) There would be no interference pattern on the second screen but it would be lighted.
(B) The second screen would be totally dark.
(C) There would be a single bright point on the second screen.
(D) There would be a regular two slit pattern on the second screen.
Answer:
(D) There would be a regular two slit pattern on the second screen.

Explanation:
At P2 is minima due to two wave fronts in opposite phase coming from, two slits S1 and S2, but there is wave fronts from S1, S2. So P2 will act as a source of secondary wavelets. Wave front starting from P2 reaches at S3 and S4 slits which will again act as two monochromatic or coherent sources and will form pattern on second screen.

Wave Optics MCQ Class 12 Chapter 10 Question 8.

In Young’s double slit experiment, the distance between the slits is reduced to half and the distance between the slits and the screen is doubled. The fringe width

(A) will be double.
(B) will be half.
(C) will remain same.
(D) will be four times.
Answer:
(D) will be four times.

Explanation:
Fringe width = β = λD/d
Initially, β = λD/d
Finally, β’ = \(\frac{\lambda \times 2 \mathrm{D}}{d / 2}\) = 4 x \(\frac{\lambda \mathrm{D}}{d}\) = 4β

MCQ Questions for Class 12 Physics Chapter 10 Wave Optics

Class 12 Wave Optics MCQ Chapter 10 Question 9.

A Young’s double slit experiment is performed with blue (wavelength 460 nm) and green light (wavelength 550 nm) respectively. If y is the distance of 4th maximum from the central fringe then

(A) yB = yG
(B) yB > yG
(C) yG > yB
(D) yB/yG = 550/460
Answer:
(C) yG > yB

Explantion:
yn = nλD/d
So, yn ∝λ
Since λG > λB
∴ø G > yB

MCQ On Wave Optics Chapter 10 Question 10.

A Young/s Double slit experiment is performed in air and in water. Which of the following relationship is true regarding fringe width (P)?

(A) βAIR > βWATER
(B) βWATER > βAIR
(C) βAIR = βWATER
(D) βWATER = 0
Answer:
(A) βAIR > βWATER

Explantion:
β ∝λ and λ.∝1/µ
So, β ∝1/µ
Since µWATER > µAIR
βAIR > βWATER

Physics MCQ Class 12 Chapter 10 Question 11.

The penetration of light into the region of geometrical shadow is known as

(A) interference of light.
(B) diffraction of light.
(C) refraction of light.
(D) polarisation of light.
Answer:
(B) diffraction of light.

Physics Class 12 MCQ Chapter 10 Question 12.

Angular width of central maxima of a single slit diffraction pattern is independent of

(A) slit width
(B) frequency of the light used
(C) wavelength of the light used
(D) distance between slit and screen
Answer:
(D) distance between slit and screen

Explanation:
Angular width = 2 sin-1 λ/d So, it is independent of D (distance between slit and screen).

MCQ Questions for Class 12 Physics Chapter 10 Wave Optics

Physics Class 12 MCQ Questions Question 13.

When a monochromatic light is passed around a file wire a diffraction pattern is observed. How the fringe width will change by increasing the diameter?

(A) Fringe width has no relation with the diameter of wire
(B) Increases
(C) Decreases
(D) Fringe width changes with change of wavelength only
Answer:
(C) Decreases

Explanation:
β = λD/d, where d is the diameter of the wire. So, if the diameter increases, fringe with decreases.

Question 14.

The main condition for diffraction to be observed is

(A) size of obstacle should be comparable to the wavelength of the wave
(B) size of obstacle should be much larger than the wavelength of the wave
(C) size of obstacle should be much smaller than the wavelength of the wave
(D) for any size of obstacle
Answer:
(A) size of obstacle should be comparable to the wavelength of the wave

Assertion And Reason Based MCQs (1 Mark each)

Directions: In the following questions, A statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as.
(A) Both A and R are true and R is the correct explanation of A
(B) Both A and R are true but R is NOT the correct explanation of A
(C) A is true but R is false
(D) A is false and R is true

Question 1.

Assertion (A): According to Huygens theory no back-ward wavefront is possible.
Reason (R): Amplitude of secondary wavelets is proportional to (1+ cos 0), where 0 is the angle between the ray at the point of consideration and direction of secondary wavelet.

Answer:
(A) Both A and R are true and R is the correct explanation of A

Explanation:
According to Huygens theory each and every point on a wavefront is the source of secondary wavelets. Secondary wavelets do not proceed backward. So the assertion is true. Kirchhoff’s explained that amplitude of secondary wavelets is proportional to (1 + cos 0), where 0 is the angle between the ray at the point of consideration and direction of secondary wavelets. In the backward direction 0 = 180°; so 1 + cos 0 = 0; so there secondary wavelets do not proceed backward. Hence assertion and both are true and the reason properly explains the assertion.

MCQ Questions for Class 12 Physics Chapter 10 Wave Optics

Question 2.

Assertion (A): Wavefront emitted by a point source of light in an isotropic medium is spherical.
Reason (R): Isotropic medium has same refractive index in all directions.

Answer:
(A) Both A and R are true and R is the correct explanation of A

Explanation:
If a medium has same refractive index at every point in all directions, then the wavefrom obtained from a point source in such a medium is spherical since wave travels in all direction with same speed. Such a medium is known as isotropic medium. So, the assertion and reasoji both are true and the reason explain the assertion properly.

Question 3.

Assertion (A): When a light wave travels from rarer to denser medium, its speed decreases. Due to this reduction of speed the energy carried by the light wave reduces.
Reason (R): Energy of wave is proportional to the frequency.

Answer:
(D) A is false and R is true

Explanation:
When a light wave travels from rarer to denser medium, its speed decreases. But this reduction of speed does not imply the loss of energy carried by the light wave. So the assertion is false. Energy of wave is proportional to the frequency of the wave which remains same in very medium. Hence there is no loss of energy. So, the reason is true.

MCQ Questions for Class 12 Physics Chapter 10 Wave Optics

Question 4.

Assertion (A): No interference pattern is detected when two coherent sources are too close to each other.
Reason (R): The fringe width is inversely proportional to the distance between the two slits.

Answer:
(A) Both A and R are true and R is the correct explanation of A

Explanation:
No interference pattern is detected when two coherent sources are too close to each other. The assertion is true.
Fringe width is proportional to 1/d. When d becomes too small, the fringe width becomes too large. So no pattern will be visible. So, the reason is also true. Reason also explains the assertion.

Question 5.

Assertion (A): For best contrast between maxima and minima in the interference pattern of Young’s double slit experiment, the amplitudes of light waves emerging from the two sources should be equal.
Reason (R): For interference, the sources must be coherent.

Answer:
(B) Both A and R are true but R is NOT the correct explanation of A

Explanation:
For destructive interference, a = ~ a2. When aj = ay only the minima will be completely dark. This will create the best contrast. So the assertion is true.
For interference, the sources must be coherent. Reason is also true. But the reason does not explain the assertion.

Question 6.

Assertion (A): Fringes of interference pattern produced by blue light is narrower than that produced by red light.
Reason (R): In Young’s double slit experiment, fringe width = XD/d

Answer:
(C) A is true but R is false

Explanation:
Fringes of interference pattern produced by blue light is narrower than that produced by red light. The assertion is true. Fringe width = XD/d. Since blue light has wavelength smaller than that of red light, blue light produces narrower fringes. So, reason is also true and explains the assertion.

MCQ Questions for Class 12 Physics Chapter 10 Wave Optics

Question 7.

Assertion (A): Diffraction takes place with all types of waves.
Reason (R): Diffraction is perceptible when the wavelength of the wave is comparable to the dimension of the diffracting device.

Answer:
(B) Both A and R are true but R is NOT the correct explanation of A

Explanation:
Diffraction is spreading of waves around obstacle. It takes place with all types of waves (mechanical, non-mechanical, transverse, longitudinal) and with very small moving particles (atom, neutron, electron etc.) which show wave like property. So, the assertion is true. Diffraction is perceptible when the wavelength of the wave is comparable to the dimension of the diffracting device. The reason is also true. But it does not explain the assertion.

Case-Based MCQS’

Attempt any 4 sub-parts out of 5. Each sub-part carries 1 mark.

I. Read the following text and answer the following questions on the basis of the same:

In one of his experiments on interference, August Jean Fresnel used a biprism to induce interference between two beams. He split a diverging beam of light into two parts by using the biprism to refract them. This resulted in two split beams which acted as if they were from two coherent sources and which therefore interfered with each other. A Fresnel Biprism is a thin double prism placed base to base and have very small refracting angle (0.5°). This is equivalent to a single prism with one of its angle nearly 179° and other two of 0.5° each.
MCQ On Wave Optics Class 12 Chapter 10
Wave Optics Class 12 MCQ Chapter 10

In Young’s double Slits experiment, a single source is split in two coherent sources. For the Young’s slits experiment, we must approximate that the slits act as point sources. This however is not the case, since the slits have finite width. In this way, it gives rise to unwanted diffraction effects that causes errors. The Fresnel biprism experiment overcomes this problem.

A Fresnel biprism is a variation of Young’s Slits experiment. When monochromatic light through a narrow slit falls on biprism that divides it into two components. One of these component is refracted from upper portion of biprism and the other one refracted through lower portion. Two virtual coherent sources formed from the original source. In this case, two virtual coherent sources are point sources and replace slits in Young’s experiment.

Question 1.

The Fresnel biprism is:

(A) a combination of two prisms with their bases in contact.
(B) a combination of two prisms with their refracting surfaces in contact.
(C) single prism
(D) not a prism actually.
Answer:
(A) a combination of two prisms with their bases in contact.

Explanation:
A Fresnel Biprism is a thin double I prism placed base to base.

MCQ Questions for Class 12 Physics Chapter 10 Wave Optics

Question 2.

Base angles of Fresnel biprism are:

(A) 179°
(B) 90°
(C) 0.50°
(D) None of these
Answer:
(C) 0.50°

Explanation:
A Fresnel Biprism is a thin double I prism placed base to base and have very small I refracting angle (0.5°). |

Question 3.

Fresnel biprism produces:

(A) two real coherent sources.
(B) two virtual coherent sources.
(C) a number of real coherent sources.
(D) a number of virtual coherent sources.
Answer:
(A) two real coherent sources.

Explanation:
When monochromatic light through a narrow slit falls on Fresnel biprism that divides it into two components. One of these component is refracted from upper portion of biprism and the other one refracted through lower portion. Thus, two virtual coherent sources formed from the original source.

Question 4.

What is the difference between the coherent sources produced by Youngf s double slit arrangement and Fresnel biprism?

(A) Young’s double slit arrangement produces virtual coherent sources whereas Fresnel biprism produces real coherent sources
(B) Young’s double slit arrangement produces coherent point sources whereas Fresnel biprism produces coherent sources which are not point sources
(C) Both Young’s double slit arrangement and Fresnel biprism produce similar coherent sources
(D) Fresnel birism produces virtual coherent point sources whereas Young’s double slit arrangement produces real coherent sources which are not point sources.
Answer:
(D) Fresnel birism produces virtual coherent point sources whereas Young’s double slit arrangement produces real coherent sources which are not point sources.

MCQ Questions for Class 12 Physics Chapter 10 Wave Optics

Explanation:
In Young’s double Slits experiment, a single source is split in two coherent sources. Both are real Both the slits have finite width. Fresnel biprism divides the beam of monochromatic light incident on it into two components. One of these component
is refracted from upper portion of biprism and the other one refracted through lower portion. Thus two virtual coherent sources are formed from the original source.

Question 5.

Which problem of Young’s double slit experiment is overcome by Fresnel biprism?

(A) Young’s double slit arrangement gives rise to irregular interference fringe pattern which is overcome by Fresnel biprism which produces coherent sources by refraction in a prism
(B) Finite width of slits in Young’s double slit experiment gives rise to unwanted diffraction effects that causes errors. This is overcome by Fresnel biprism by producing virtual coherent point sources.
(C) Young’s double slit arrangement produces interference fringe pattern of low intensity which is overcome by Fresnel biprism.
(D) All of the above
Answer:
(B) Finite width of slits in Young’s double slit experiment gives rise to unwanted diffraction effects that causes errors. This is overcome by Fresnel biprism by producing virtual coherent point sources.

Explanation:
In Young’s double Slits experiment, a single source is split in two coherent sources. For the Young’s slits experiment, we must approximate that the slits act as point sources. This however is not the case, since the slits have finite width. In this way, it gives rise to unwanted diffraction effects that causes errors. The Fresnel biprism experiment overcomes this problem.

When monochromatic light through a narrow slit falls on biprism that divides it into two components. One of these component is refracted from upper portion of biprism and the other one refracted through lower portion. Two virtual coherent point sources are formed from the original source.

II. Read the following text and answer the following questions on the basis of the same:

Diffraction in a hall:
A and B went to purchase a ticket of a music programme. But unfortunately only one ticket was left. They purchased the single ticket and decided that A would be in the hall during the 1st half and B during the 2nd half. Both of them reached the hall together. A entered the hall and found that the seat was behind a pillar which creates an obstacle. He was disappointed. He thought that he would not be able to hear the programme properly. B was waiting outside the closed door. The door was not fully closed. There was a little opening. But surprisingly, A could hear the music programme.

This happened due to diffraction of sound. The fact we hear sounds around corners and around barriers involves both diffraction and reflection of sound. Diffraction in such cases helps the sound to ‘bend around” the obstacles. In fact, diffraction is more pronounced with longer wavelengths implies that we can hear low frequencies around obstacles better than high frequencies.

MCQ Questions for Class 12 Physics Chapter 10 Wave Optics

B was outside the door. He could also hear the programme. But he noticed that when the door opening is comparatively less he could hear the programme even being little away from the door. This is because when the width of the opening is larger than the wavelength of the wave passing through the gap then it does not spread out much on the other side. But when the opening is smaller than the wavelength more diffraction occurs and the waves spread out greatly – with semicircular wavefront. The opening in this case functions as a localized source of sound.
MCQ Of Wave Optics Class 12 Chapter 10

Question 1.

A and B could hear the music programme due to phenomenon named

(A) interference.
(B) scattering.
(C) diffraction.
(D) dispersion.
Answer:
(C) diffraction.

Explanation:
The fact we hear sounds around corners and around barriers involves both diffraction and reflection of sound.

Question 2.

Diffraction is more pronounced with ………… wavelengths.

(A) Longer
(B) Shorter
(C) fluctuating
(D) all
Answer:
(A) Longer

Explanation:
In fact, diffraction is more pronounced with longer wavelengths

Question 3.

The minimum and maximum frequencies in the musical programme were 550 Hz and 10 kHz. Which frequency was better audible around the pillar obstacle?

(A) 10 kHz
(B) 550 kHz
(C) Mid frequency
(D) The complete frequency range
Answer:
(A) 10 kHz

Explanation:
In fact, diffraction is more pronounced with longer wavelengths implies that you can hear low frequencies around obstacles better than high frequencies.

MCQ Questions for Class 12 Physics Chapter 10 Wave Optics

Question 4.

Diffraction of sound takes place more when :

(A) sound is diffracted through an opening having width equal to the wavelength of the sound.
(B) sound is diffracted through an opening having width more than the wavelength of the sound.
(C) sound is diffracted through an opening having width less than the wavelength of the sound.
(D) diffraction of sound does not depend on the width of the opening.
Answer:
(C) sound is diffracted through an opening having width less than the wavelength of the sound.

Explanation:
When the width of opening is comparatively less than the wavelength of sound wave, the sound spread out much better i.e. better diffraction occurs. When the width of the opening is larger than the wavelength, the wave passing through the opening does not spread out much on the other side.

Question 5.

How the waveform will look like outside the door of the hall?

(A) Sound repeater
(B) Sound reflector
(C) Localized sound source
(D) None of the above
Answer:
(C) Localized sound source

Explanation:
spreads out well through a gap whose width is slightly smaller than the wavelength of the sound wave as if it is a localised source of sound.

MCQ Questions for Class 12 Physics with Answers