CBSE Class 12

NCERT Solutions for Class 12 History Chapter 11 Rebels and the Raj The Revolt of 1857 and its Representations are part of NCERT Solutions for Class 12 History. Here we have given NCERT Solutions for Class 12 History Chapter 11 Rebels and the Raj The Revolt of 1857 and its Representations.

NCERT Solutions for Class 12 History Chapter 11 Rebels and the Raj The Revolt of 1857 and its Representations

Question 1.
Why did the mutinous sepoys in many places turn to erstwhile rulers to provide leadership to the revolt ?
Solution :
The mutinous sepoys in many places turn to erstwhile rulers to provide leadership to the revolt due to the following factors :

1. To acquire a kind of legitimacy : On reaching Delhi the Sepoys of Meerut demanded that the Mughal emperor give them his blessing and to become their leader. Bahadur Shah had no other option but to become their nominal leader. The revolt thus acquired a kind of legitimacy because it could now be carried on in the name of the Mughal emperor. Similarly, Nana Sahib the successor to Peshwa Baji Rao II became the leader of the rebellion in Kanpur.
2. In Jhansi, Rani Lakshmi Bai was forced by the popular pressure to assume the leadership of the uprising.
3. There was also need for organisation that could carry on the rebellious activities in a proper manner. That guidance could be provided by the erstwhile rulers like Nana Sahib, Jhansi ki Rani and others.

Question 2.
Discuss the evidence that indicates planning and coordination on the part of the rebels.
Solution :
The rebellion was not abrupt and sporadic but to a great extent done with planning and care. This is brought out by the following points:

1. The rebels decided to strike when the large part of the British army was in Burma.
2. The time chosen for the rebellion was summer that is very hostile weather condition for the British. Summer was also the season when the entire countryside would be easy to navigate.
3. To spread the message of rebellion, the rebels used symbols bread and lotus from village to village.
4. Efforts were made to maintain Hindu-Moslem unity. Whenever an area would fail under rebel control, cow slaughter was banned.

Question 3.
Discuss the extent to which religious beliefs shaped the events of 1857.
Solution :
The religious beliefs shaped the events of 1857 in a significant way as mentioned below:

• The immediate cause of the revolt by the sepoys at Meerut was the bullets that were coated with the fat of cows and pigs and bitting those bullets would corrupt the caste and religion of both the Hindus and Muslims.
• There was also rumour that the British had mixed the bone dust of cows and pigs into the flour that was sold in the market.
• There was also fear and suspicion that the British wanted to convert Indians to Christianity

Question 4.
What were the measures taken to ensure unity among the rebels?
Solution :
A very important element of the revolt of 1857 was the unity shown by Hindus and Moslems in the struggle against the foreign rule. First the immediate cause of the rebellion was the use of cartridge greased with fat of cow and pig, angering Hindus and Moslems alike. After the rebels marched to Delhi, they declared the Mughal emperor Bahadurshah their all India leader. Thus, the Mughal emperor was the leader of Hindus and Muslems alike. Both Hindus and Muslims respected each others’ religious sentiments. Whenever a new area fell into the control of rebels, cow slaughter was made illegal to respect Hindu sentiments. Thus, Hindu-Muslim unity was the hallmark of the mutiny.

Question 5.
What steps did the British take to quell the uprising ?
Solution :
The British took the following steps to quell the uprising :

• The British passed a series of laws to quell the insurgency. By these Acts passed in May and June 1857, the whole of North India was put under martial law.
• The military officers and even ordinary Britons were given the power to try and punish Indians suspected of rebellion.
• The ordinary processes of law and trial were suspended and it was decided that rebellion would have only one punishment – death.
• The reinforcements were brought in from Britain.
• The British used military power on a gigantic scale.
• The British tried to break up the unity between big landholders and peasants in Uttar Pradesh by promising to give back to the big landholders their estates. Rebel landholders were dispossessed and the loyal rewarded.

Question 6.
Why was the revolt particularly widespread in Awadh? What prompted peasants, taluqdars and zamindar to join the rebellion?
Solution :
The Mutiny of 1857 which was rebellions of the sepoys of the Company, turned into mass uprising in certain areas of the country. The most prominent was the area that was erstwhile part of the kingdom of Oudh. One report of the government says that 75 percent of men in Oudh were involved in the rebellion. Following are the main reasons why it took a mass uprising in that area:
1. Unceremonious removal of the Nawab: The nawab of Oudh Wazid Ali Shah was removed by Dalhosies on the pretext of poor governance. The removal was looked upon by the people as high handed and insult to them. The local people sympathized with the nawab. Thus, the public sentiment was against the British government that got a vent out during the revolt.

2. The ruling elite of Oudh: The ruling elite of Oudh during the rule of Nawab was dislodged from the position of power and prestige. The ruling elite that was employed in the Court of nawab and other senior position was rendered unemployed. They began to feel hardships and it had a cascading impact, the people dependent on them also slipped in depravity. For all such people British rule was the culprit.

3. The agrarian unrest: There was strong anti-British sentiment in Oudh from the level of Talukdars to peasants. Talukdars were rich landlords collecting taxes and enforcing law and order. They enjoyed a lot of autonomy as long as they paid revenue to nawab. The talukdars faced the heavy hands of the British masters. Their autonomy ceased to exist. Their foot soldiers were disarmed and disbanded. The peasants were oppressed more as hardships engulfed the Talukdars. Peasants were over assessed and forced to pay higher taxes than in past.

4. Muslim Anger: The Muslems in North India looked upon British as snatcher of their empire. The Moslems thought themselves as natural rulers of India who were displaced from this position by the British. The Oudha which has the substantial Moslem population burst out against the Company’s rule when it got an opportunity viz. the mutiny of 1857. In fact the then government of East India Company described the mass uprising of Oudh as Moslem conspiracy.

Question 7.
What did the rebels want ? To what extent did the vision of different social groups differ ?
Solution :
(a) The Azamgarh Proclamation of 25 August, 1857 is the main source of information about what the rebels wanted. The objects mentioned in this Proclamation are as given below :

• Zamindars : lb reduce the Jumas, to protect their dignity and honour and to have absolute rule in their territories.
• Merchants : End of fraudulent practices, Right to trade of every article without exception both by land and water to all the native merchants of India.
• Public servants : Better salaries and appointment to high posts.
• Artisans : Employment in the service of the Kings, rajahs and the rich.
• Pundits, Fakirs and other learned persons : To protect their religions.

(b) Besides the objects mentioned in the Azamgarh Proclamation, the other objects of the rebels were as follows :

• To restore the life of people as it existed before the British rule.
• To save their livelihood, their faith, their honour and dignity.
• To have an egalitarian society by overturning traditional hierarchies.
• To restore the pre-British world of the eighteenth century i.e., Mughal world.

(c) From above it is clear that the vision of different groups differed from each other according to their problems. But on the whole they were against the British rule and wanted to get rid of it.

Question 8.
What do visual representations tell us about the revolt of 1857 ? How do historians analyse these representations ?
Solution :
(a) The visual representations give us the following information :

1. Information about saviours: Paintings such as “Relief of Lucknow” depicts British heroes – Colin Campbell, Outram and Havelock who saved the British and repressed the rebels in Lucknow.
2. Painting showing helpless and innocent women in fear of dishonour, violence and death. “In Memoriam’ is a painting that shows the condition of British women dming mutiny and what the mutineers were doing with them.
3. Women’s struggle to save their honour and their life. The sketch showing Miss Wheeler as defending herself against sepoys in Kanpur shows that the women too tried to save themselves. It has, however, a deeper religious connotation. It was a battle to save the honour of Christianity.
4. Vengeance and retribution : The visual representations such as Justice — an allegorical female figure in an aggressive posture depicts that there was great demand for a repressive policy and violent reprisal.
5. The performance of terror: The “British Lion’s Vengeance on the Bengal Tiger” and “Execution of Mutineers in Peshawar” proves that the British followed a repressive policy to create terror among the Indians.
6. No time for clemency: ‘The Clemency of Canning’ is a cartoon that shows that there was no time for leniency against the Indians.
7. Nationalist imageries : The nationalist considered it a First War of Independence. Rani Lakshmi Bai and others were depicted as heroic figures. Usually, Rani was portrayed in battle armour that symbolised her determination to resist injustice and alient rule.

Thus, the paintings and other visual representation tell us about the feeling of the people in India and Britain.

(b) The historians consider these pictorial images produced by the British as well as by the Indians an important source of information about the feelings and reaction of the people at that time. These images reflect the public opinion which influenced the policies of the British government. On the other hand, the national imageries depict the national feelings of the Indians.

Question 9.
Examine any two sources presented in the chapter, choosing one visual and one text, and discuss how these represent the point of view of the victor and the vanquished.
Solution :
(a)

The above picture shows Secundrah Bagh, Lucknow. This place was once the pleasure garden which was built by Nawab Wajid Ali Shah. After the rebellion, the British forces led by Cambell killed 2000 rebel sepoys who held the place in 1857. The skeleton strewn on the ground are meant to be a cold warning of the futility of rebellion. This shows that in Awadh where according to an estimate three-fourths of adult male population was in rebellion, too could not succeed and were under control in March 1858.

(b) Villagers as rebels
An officer reporting from rural Awadh (spelt as Oude in the following account) noted : The Oude people are gradually pressing down on the line of communication from the North … the Oude people are villagers … these villagers are nearly intangible to Europeans melting away before them and collecting again. The Civil Authorities report these villagers to amount to a very large number of men, with a number of guns.’

The above source depicts the way in which villagers in Awadh fought with the British forces. They could not be defeated easily because they used to melt away before the British but soon after they collected again. Thus, it was very difficult for the British to control them. The fighting in Awadh continued till March 1858. This shows that in Awadh the rebellion was spread. On the other hand, it shows that inspite of difficulties, the British were determined to suppress the rebellion. The forces were used on a gigantic scale and ultimately Awadh was brought under control.

We hope the NCERT Solutions for Class 12 History Chapter 11 Rebels and the Raj The Revolt of 1857 and its Representations help you. If you have any query regarding NCERT Solutions for Class 12 History Chapter 11 Rebels and the Raj The Revolt of 1857 and its Representations, drop a comment below and we will get back to you at the earliest.

NCERT Solutions for Class 12 History Chapter 2 Kings, Farmers and Towns Early States and Economies are part of NCERT Solutions for Class 12 History. Here we have given NCERT Solutions for Class 12 History Chapter 2 Kings, Farmers and Towns Early States and Economies.

NCERT Solutions for Class 12 History Chapter 2 Kings, Farmers and Towns Early States and Economies

Question 1.
Discuss the evidence of craft production in Early Historic cities. In what ways is this different from the evidence from Harappan cities ?
Solution :
Various evidences of craft production in Early Historic cities have been found. These include fine pottery bowls and dishes, with a glossy finish, known as Northern Black Polished Ware, probably used by rich people and ornaments, tools, weapons, vessels, figurines, made of a wide range of materials – gold, silver, copper, bronze, ivory, glass, shell and terracotta. Iron was also used for making plough share, weapons and tools as well as to meet the growing demands in the cities.

On the other hand, the craft production in the Harappan cities included bead-making, shell¬cutting, metal-working, seal-making and weight-making. The material used was stones, jasper, crystal, quartz, copper, bronze, gold, shell, faience and terracotta.

The evidence of craft production in the Harappan civilisation have been found from excavations. The evidences for the Early Historic cities have been found from excavations as well as from inscriptions.
Another difference is that there were guilds in the early Historic cities. These were organisations of craft producers and merchants. These guilds or shrenis probably procured raw materials, regulated production and marketed the finished product.

Question 2.
Describe the salient features of Mahajanapadas.
Solution :
Mahajanapadas were states that existed between 6th and 4th BC centuries. Buddhist and Jain texts mention sixteen Mahajanapadas. The name of all these are not uniform in all texts but some names are common and uniform which means they were the powerful ones. These Mahajanapadas are Vajji, Magadha, Kaushal, Kuru, Panchal, and Gandhar.

The important features of the Mahajanapadas are as follows.

1. Most of the Mahajanapadas were ruled by powerful kings. However, there were some Mahajanapadas where rule was in the hands of people, we call them republics. In some states the king and the subject had collective control on the economic resources of the state.
2. Every Mahajanapadas had its own capital. The capital normally would be surrounded by fort. The fortification of the capital was needed for protection and economic resources.
3. It was around 6th Qentury BC, Brahmins began to compile scripture called “Dharmshastra” which states rules of morality including that of monarch. Herein it was mentioned that the king should be Kshatriya.
4. The main job of the king was collection of taxes from farmers, traders, craftsmen. They also accepted donations.
5. It was considered fair to plunder neighbouring countries for riches.
6. Gradually Mahajanapadas began to have full time army and officials. Soldiers were from the ranks of farmers.

Question 3.
How do historians reconstruct the lives of ordinary people?
Solution :
Ordinary people rarely left accounts of their thoughts and experiences. The historians reconstruct their lives by examining stories contained in anthologies such as the Jatakas and the Panchatantra. For example, one story known as the Gandatindu Jataka describes the plight of the subjects of a wicked king. The subjects included elderly women and men, cultivators, herders, village boys and even animals. When the king went in disguise to find out what his subjects thought about him, each one of them cursed him for their miseries, complaining that they were attacked by robbers at night and by tax collectors during the day. As a result of it, people abandoned their village and went to live in the forest.

Question 4.
Compare and contrast the list of things given to the Pandyan chief (Source 3) with those produced in the village of Danguna (Source 8). Do you notice any similarities or differences?
Solution :
(a) The defeated people gave the following things to the Pandya chief as a mark of respect to the victorious king : Ivory, fragrant wood, fans made of the hair of deer, honey, sandalwood, red ochre, antimony, turmeric, cardamom, pepper, coconuts, mangoes, medicinal plants, fruits, onions, sugarcane, flowers, areca*nut, bananas, baby tigers, lions, elephants, monkeys, bear, deer, musk deer, fox, peacocks, musk cat, wild cocks and speaking parrots.
(b) The village of Danguna produced the following things : Grass, animal hides, charcoal, fermenting liquors, salt, khadira trees, flowers and milk.
(c)

1. Similarities : Both the lists contain the things of daily use such as honey, turmeric, i cardamom, pepper, mangoes, fruits, onions, flowers (Source 3) and grass, salt, flowers and milk (Source 8).
2. Differences : The things given to the Pandya chief included precious things such as ivory, fragrant wood, sandalwood and wild animals like tigers, lions, elephants, wild cocks. These things and animals prove that the forest people were brave and their economic condition was good. On the other hand, the things of the Danguna village did not include precious things. It included things such as grass, animal hides, flowers and milk which prove that they were ordinary people and their economic condition was bad. That was probably the reason for granting them various exemptions by Prabhavati Gupta.

Question 5.
List some of the problems faced by the epigraphists.
Solution :
The specialists who study inscriptions are called Epigraphists. Some of the important problems they encounter when they try to decipher inscriptions are as follows:

1. Many of the inscriptions are not found in proper shape, they are partly damaged, hence deciphering them becomes a knotty problem.
2. The inscriptions are written from the point of view of those who have created it. Hence, in order to get an impartial understanding, we need to go beyond the written words, get into its interpretations.
3. Many of the inscriptions have descriptions in symbolic words. Hence deciphering them have become difficult.
4. Sometimes the inscriptions are engrafted in very light colors. Hence, deciphering them becomes difficult.

6. Question 6.
Solution :
Asokan inscriptions mention all the main features of the administration of the Mauryan Empire. Thus, the features of the administration are evident in the inscriptions of the Asokan age. The important features of the same are as follow:
1. The capital of the Mauryan Empire was Pataliputra. Apart from the capital there ‘ were four other centres of political power in the empire. They were Taxila, Ujjaini,
Tosali and Suvamagiri.
2. Committee and subcommittees were formed to run the administration and safety of boundaries. Megasthenes has mentioned that there were one committee and six sub-committees. The six subcommittees and their areas of activities are as follows:
(i) The first sub committee looked after navy.
(ii) The second sub committee looked after transport and communications.
(iii) The third sub committee looked after infantry.
(iv) The fourth sub committee had the responsibility of horses.
(v) The fifth had the responsibility of chariots.
(vi) The sixth had the responsibility of elephants.
3. Strong network of roads and communications were established. It is notable that no large empire can be maintained in the absence of the same.
4. Asoka made an attempt to keep the empire united by the philosophy of Dhamma. Dhamma are nothing but moral principles that actuated people towards good conduct. Special officers called Dhamma Mahamtras were appointed to propagate Dhamma. In fact Romila Thapar has made it the most important element of the Asokan state’s governing principle.

Question 7.
This is a statement made by one of the best-known epigraphists of the twentieth century. D.C. Sircar: “There is no aspect of life, culture and activities of the Indians that is not reflected in inscriptions.” Discuss.
Solution :
(a) The statement of D.C. Sircar that there is no aspect of life, culture and activities of the Indians that is not reflected in inscriptions does not seem to be correct because not everything that is politically or economically significant was necessarily recorded in inscriptions. Some examples are given below :

• Routine agricultural practices and the joys and sorrows of daily existence find no mention in inscriptions.
• The inscriptions generally focus on grand, unique events.
• The content of inscriptions almost invariably projects the perspective of the person who commissioned them. For example, in some inscriptions Asoka claims that earlier rulers had no arrangements to receive reports about the people. This does not seem to be correct.

(b) The inscriptions give us only the following information :

• Information about the administration particularly major political centres.
• Asoka’s Dhamma and its propagation by special officers known as the dhamma mahamatta.

Question 8.
Discuss the notions of kingship that developed in the post-Maury an period.
Solution :

1. The main notion that developed in the post-Mauryan period was that of divine kings. The kings identified themselves with a variety of deities to claim high status. This strategy was adopted by the Kushanas who ruled over a vast kingdom extending from Central Asia to northwest India.
2. Colossal statues of Kushana rulers were installed in a shrine at Mat near Mathura and in Afghanistan. This indicates that the Kushanas considered themselves godlike.
3. Many Kushana rulers adopted the title devaputra, or “son of god”. It was possibly inspired by Chinese rulers who called themselves sons of heaven.

Question 9.
To what extent were agricultural practices transformed in the period under consideration?
Solution :
The agricultural practices were transformed in the period under consideration i.e., 600 BCE – 6OO CE in the following ways :

• There was a shift to plough-agriculture in fertile alluvial river valleys such as those of Ganga and the Kaveri from c. sixth century BCE.
• The iron-tipped ploughshare was used to turn the alluvial soil in areas which had high rainfall.
• In some parts of the Ganga valley, production of paddy was dramatically increased by the introduction of transplantation.
• Those living in hilly tracts in the north-eastern and central parts of the subcontinent practised hoe agriculture, which was much better suited to the terrain.
• Irrigation was used to increase agricultural production. Wells, tanks, and canals were used for this purpose. Communities as well as individuals organised the construction of irrigation works.

We hope the NCERT Solutions for Class 12 History Chapter 2 Kings, Farmers and Towns Early States and Economies help you. If you have any query regarding NCERT Solutions for Class 12 History Chapter 2 Kings, Farmers and Towns Early States and Economies, drop a comment below and we will get back to you at the earliest.

NCERT Solutions for Class 12 Physics Chapter 3 Current Electricity

NCERT Solutions for Class 12 Physics Chapter 3 Current Electricity part of NCERT Solutions for Class 12 Physics. Here we have given. NCERT Solutions for Class 12 Physics Chapter 3 Current Electricity

Question 1.
The storage battery of a car has an e.m.f. of 12 V. If the internal resistance of the battery is 0.4Ω, what is the maximum current that can be drawn from the battery ?
Answer:

Question 2.
A battery of e.m.f. 10 V and internal resistance 3Ω is connected to a resistor. If the current in the circuit is 0.5 A, what is the resistance of the resistor ? What is the terminal voltage of the battery when the circuit is closed ?
Answer:

Question 3.
(a) Three resistors IΩ, 2 Ωand 3 Ω are combined in series. What is the total resistance of the combination?
(b) If the combination is connected to a battery of e.m.f. 12 V and negligible internal resistance, obtain the potential drop across each resistor.
Answer:

Voltage drop across R₃ is given by, V₃ = IR₃ = 2 x 3 = 6V.

Question 4.
(a) Three resistors 2 Ω, 4 Ω, and 5 Ω, are combined in parallel. What is the total resistance of the combination?
(b) If the combination is connected to a battery of e.m.f. 20 V and negligible internal resistance, determine the current through each resistor, and the total current drawn from the battery.
Answer:

Question 5.
At room temperature (27.0 °C) the resistance of a heating element is 100 Ω. What is the temperature of the element if the resistance is found to be 117 Ω, given that the temperature coefficient of the material of the resistor is 1.70 x 10^-4 °C^-1.
Answer:

Question 6.
A negligibly small current is passed through a wire of length 15 m and uniform cross-section 6.0 x 10^-7 m², and its resistance is measured to be 50 Ω. What is the resistivity of the material at the temperature of the experiment ?
Answer:

Question 7.
A silver wire has a resistance of 2.1 Ω at 27.5 °C, and a resistance of 2.7 Ω at 100 °C. Determine the temperature coefficient of resistivity of silver.
Answer:

Question 8.
A heating element using nichrome connected to a 230 V supply draws an initial current of 3.2 A which settles after a few seconds to a steady value of 2.8 A. What is the steady temperature of the heating element if the room temperature is 27.0 °C ? Temperature co­efficient of resistance of nichrome averages over the temperature range involved is 1.70 x 10^-4 °C^-1.
Answer:


Question 9.
Determine the current in each branch of the network shown in Figure

Answer:

Question 10.
(a) In a meter bridge (Figure), the balance point is found to be at 39.5 cm from the end A, when the resistor Y is of 12.5 Ω. Determine the resistance of X. Why are the connections between resistors in a Wheatstone or meter bridge made of thick copper strips?

(b) Determine the balance point of the bridge above if X and Y are interchanged.
(c) What happens if the galvanometer and cell are interchanged at the balance point of the bridge? Would the galvanometer show any current? (C.B.S.E. 2005)
Answer:


Question 11.
A storage battery of e.m.f. 8.0 V and internal resistance 0.5 Ω is being charged by a 120 V dc supply using a series resistor of 15.5 Ω. What is the terminal voltage of the battery during charging? What is the purpose of having a series resistor in the charging circuit ?
Answer:
During charging,
V = E + I(r + R)

Question 12.
In a potentiometer arrangement, a cell of e.m.f. 1.25 V gives a balance point at 35.0 cm length of the wire. If the cell is replaced by another cell and the balance point shifts to 63.0 cm, what is the e.m.f. of the second cell ?
Answer:

Question 13.
The number density of free electrons in a copper conductor estimated in Example 3.1 is 8.5 x 10²⁸ m³. How long does an electron take to drift from one end of a wire 3.0 m long to its other end? The area of cross­section of the wire is 2.0 x 10^-6 m² and it is carrying a current of 3.0 A.
Answer:

Question 14.
The earth’s surface has a negative surface charge density of 10^-9 cm^-2. The potential difference of 400 kV between the top of the atmosphere and the surface results (due to the low conductivity of the lower atmosphere) in a current of only 1800 A over the entire globe. If there were no mechanism of sustaining atmospheric electric Held, how much time (roughly) would be required to neutralise the earth’s surface ? (This never happens in practice because there is a mechanism to replenish electric charges, namely the continual thunderstorms and lightning in different parts of the globe.)
(Radius of earth = 6.37 x 10⁶ m.)
Answer:

Question 15.
(a) Six lead-acid type of secondary cells each of e.m.f. 2.0 V and internal resistance 0.015 Ω are joined in series to provide a supply to a resistance of 8.5 Ω. What are the current drawn from the supply and its terminal voltage ?
(b) A secondary cell after long use has an e.m.f. of 1.9 V and a large internal resistance of 380 Ω. What maximum current can be drawn from the cell ? Could the cell drive the starting motor of a car ?
Answer:

It cannot be used for starting motor of a car because large current is needed to start the car.

Question 16.
Two wires of equal length, one of aluminium and the other of copper have the same resistance. Which of the two wires is lighter? Hence explain why aluminium wires are preferred for overhead power cables. (P_AL = 2.63 x 10⁸ Ω m, P_cu= 1.72 X 1(H Ω m. Relative density of A1 = 2.7, of Cu = 8.9.)
Answer:


Aluminium is lighter, so it is used for overhead power cables.

Question 17.
What conclusion can you draw from the following observations on a resistor made of alloy manganin?

Answer:
It indicates that Ohm’s law i.e.V α I is valid for a wide range.
Resistivity of Manganin remains nearly same with change in temperature.

Question 18.
Answer the following questions :
(a) A steady current flows in a metallic conductor of non-uniform cross-section. Which of these quantities is constant along the conductor : current, current density, electric field, drift speed?
(b) Is Ohm’s law universally applicable for all conducting elements? If not, give examples of elements which do not obey Ohm’s law.
(c) A low voltage supply from which one needs high currents must have very low internal resistance. Why?
(d) A high tension (HT) supply of, say, 6 kV must have a very large internal resistance. Why?
Answer:
(a) Current
(b) No. Devices are and vacuum tubes, semiconductor diodes, transistors, thermisters, thyristors, etc.
(c) Lesser the value of ‘r’, the higher the current.

Clearly low r will ensure high current
(d) If internal resistance is not large, then the heavy current drawn during an accidental short circuit can damage the supply.

Question 19.
Choose the correct alternative:
(a) Alloys of metals usually have (greater/less) resistivity than that of their constituent metals.
(b) Alloys usually have much (lower/higher) temperature coefficients of resistance than pure metals.
(c) The resistivity of the alloy manganin is nearly independent of/increases rapidly with the increase of temperature.
(d) The resistivity of a typical insulator (e.g., amber) is greater than that of a metal by a factor of the order of (10²²/10)³).
Answer:
(a) Greater
(b) Lower
(c) Nearly independent
(d) 10²²

Question 20.
(a) Given n resistors each of resistance R, how will you combine them to get the
(i) maximum (ii) minimum effective resistance? What is the ratio of the maximum to minimum resistance?
(b) Given the resistances of 1 Q, 2 G, 3 Q, how will combine them to get an equivalent resistance of (i) (11/3)Ω (ii) (11/5) Ω, (iii) 6 Ω, (iv) (6/11) Ω?
(c) Determine the equivalent resistance of networks shown in the figure. (N.C,E.R,T.)
Answer:

(i) Maximum resistance can be obtained by combining them in series with each other.
The maximum resistance R_max = R + R + R + ……………..n times = nR.
(ii) Minimum effective resistance can be obtained by combining them in parallel with each other. Minimum resistance R_max is found as

Question 21.
Determine the current drawn from a 12 V supply with internal resistance 0.5Ω by the infinite network shown in the figure. Each resistor has 1 Ω resistance. (N.C.E.R.T.)

Answer:
Let the total resistance of the circuit be Z and a set of three resistors of value R each is connected to it as shown in the figure.

Question 22.
The figure shows a potentiometer with a cell of 2.0 V and internal resistance of 0.40 Ω maintaining a potential drop across the resistor wire AB. A standard cell which maintains a constant e.m.f. of 1.02 V (for very moderate currents up to a few mA) gives a balance point at 67.3 cm length of the wire. To ensure very low currents drawn from the standard cell, very high resistance of 600 kΩ is put in series with it, which is shorted close to the balance point. The standard cell is then replaced by a cell of unknown e.m.f. e and the balance point found similarly, turns out to be at 82.3 cm length of the wire.

(a) What is the value e?
(b) What purpose does the high resistance of 600 kΩ have?
(c) Is the balance point affected by this high resistance?
(d) Is the balance point affected by the internal resistance of the driver cell?
(e) Would the method work in the above situation if the driver cell of the potentiometer had an e.m.f. of 1.0 V instead of 2.0 V?
(f) Would the circuit work cell for determining an extremely small e.m.f., say of the order of a few mV (such as the typical e.m.f. of a Thermo ­couple not, how will you modify the circuit?
Answer:

(b) It allows only a small current to flow through the galvanometer when the circuit is not balanced.
(c) No
(d) No
(e) No
(f) No. The circuit will not work (E ∝ l).
The circuit can be modified by putting a suitable resistor ‘R’ in series with the wire AB.

Question 23.
The figure shows a potentiometer circuit for the comparison of two resistances. The balance point with a standard resistor R = 10.0 Ω is found to be 58.3 cm, while that with the unknown resistance X is 68.5 cm. Determine the value of X. What might you do if you failed to find a balance point with the given cell of emf ε?
Answer:

(b) We fail to get the balance point with the given cell of emf E, if the potential difference across the wire AB. In order to obtain the balance point with the given cell E, either the emf of the auxiliary⁷ battery (between A and B) should be increased or a suitable resistance should be put in series with R and X (so as to decrease the potential drop across the wire AB).

Question 24.
The figure shows a 2.0 V potentiometer used for the determination of internal resistance

1.5 V cell. The balance point of the cell in open circuit is 76.3 cm. When a resistor of
9.5 Ω is used in the external circuit of the cell, the balance point shifts to 64.8 cm length of the potentiometer wire. Determine the internal resistance of the cell.
Answer:

We hope the NCERT Solutions for Class 12 Physics Chapter 3 Current Electricity, help you. If you have any query regarding NCERT Solutions for Class 12 Physics Chapter 3 Current Electricity, drop a comment below and we will get back to you at the earliest.

NCERT Solutions for Class 12 Chemistry Chapter 15 provides answers to the questions provided in the textbook. The answers are accompanied by diagrammatic representations for better understanding. Also, the solutions are explained in such a language that the students find easy to understand.

NCERT Solutions are beneficial for the students appearing in UP board, MP board, CBSE, Gujarat board, etc. Also the students appearing for competitive exams such as NEET and JEE will find the NCERT Solutions for Class 12 Chemistry beneficial.

NCERT Solutions for Class 12 Chemistry Chapter 15 Polymers

Polymers are very large molecules having high molecular mass. These are also known as macromolecules. This chapter explains the mechanical properties and applications of polymers. The classification of polymers is also described in detail.

The chapter gives an overview of different polymerization reactions. The chapter explains that the polymers are the backbone of four major industries, plastic, elastomers, fibres and paints.

NCERT INTEXT QUESTIONS

Question 1.
What are polymers?
Answer:
The word polymer has a Greek origin where poly means many and mers or meros stands for unit or part. Thus, the polymer may be defined as a substance of a high molecular mass (10³ – 10⁷ u) formed by the combination of a large number of simple
molecules called monomers by chemical bonds. The process by which monomers are converted into polymers is called polymerization.

Question 2.
How are polymers classified on the basis of structure?
Answer:
On the basis of structure, polymers are classified as:
(i) Linear polymers in which the monomers are joined together to form long straight chains of polymer molecules. Forex: HDPE, PVC, nylons, etc.
(ii) Branched-chain polymers in which the monomers not only join in a linear fashion but also form branches of different lengths along the main chain. For ex: LDPE, glycogen, etc.
(iii) Cross-linked polymers in which the initially formed linear polymer chains join together to form a 3D network structure. For ex: bakelite, Urea-formaldehyde resin, etc.

Question 3.
Write the names of the monomers of the following polymers:

Answer:
(i) The polymer is Nylon 66. Its monomer units are hexamethylenediamine and adipic acid.
(ii) The polymer is Nylon 6. Its monomer units are of caproilactum.
(iii) The polymer is Teflon. Its monomer units are of tetrafluoroethylene.

Question 4.
Classify the following as addition and condensation polymers:
(i) Terylene
(ii) Bakelite
(iii) Polyvinyl chloride
(iv) Polythene
Answer:
(i) Condensation polymer
(ii) Condensation polymer
(iii) Addition polymer
(iv) Addition polymer

Question 5.
Explain the difference between Buna-N and Buna-S.
Answer:
Both Buna-N and Buna-S are synthetic rubber and are co-polymers in nature. They differ in their constituents.
Buna-N: Constituents are : buta-1, 3-diene and acrylonitrile.
Buna-S: Constituents are : buta-1, 3-diene, and styrene. They condense in the presence of Na.

Buna – S: It is a co—polymer of 1. 3 – butadiene and styrene and is prepared by the polymerisation of these components in the
ratio of 3 : 1 in the presence of sodium.

Buna-N (Nitrile rubber):  h is a co-polymer of buta-1. 3-diene and acrylonitrile. It is formed as follows:

Question 6.
Arrange the following polymers in increasing order of their intermolecular forces :
(i) Nylon-66, Buna-S, Polythene
(ii) Nylon-6, Neoprene, Polyvinyl chloride
Answer:
We have studied the classification of polymers based upon intermolecular forces. These follow the order :
Elastomers < Plastics < Fibres.

The polymers listed may be arranged in increasing order of intermolecular forces as follows :
(i) Buna-S (Elastomer) < Polythene (Plastic) < Nylon-66 (Fibre)
(ii) Neoprene (Elastomer) < Polyvinyl chloride (Plastic) < Nylon-6 (Fibre).

NCERT Exercise

Question 1.
Explain the terms polymers and monomers.
Answer:
Polymers are a high molecular mass of macromolecules composed of repeating structural units derived from monomers. Polymers have a high molecular mass (10³-10⁷u). In a polymer, various monomer units are joined by strong covalent bonds. Polymers can be natural as well as synthetic. Polythene, rubber, and nylon 6,6 are examples of polymers.

Monomers are simple, reactive molecules that combine with each other in large numbers through covalent bonds to give rise to polymers. For example ethene, propene, styrene, vinyl chloride.

Question 2.
What are natural and synthetic polymers? Give two examples of each.
Answer:
Natural polymers:
Natural polymers are high molecular mass macromolecules and are found in nature mainly in plants and animals. For example, protein, nucleic acids, starch, cellulose, etc.

Synthetic polymer:
Synthetic polymers are man-made high molecular mass macromolecules. For example, plastics (Polyethene, P.V.C.), synthetic fibers (Polyesters, Nylon-6,6), synthetic rubber (Neoprene, Buna-S), etc.

Question 3.
Distinguish between the terms homopolymer and copolymer and give one example of each. (C.B.S.E. Outside Delhi 2008, Pb. Board 2008)
Answer:
A polymer in which the monomers are the same is called a homopolymer. For example, polystyrene is made from styrene only.
A polymer in which the monomers are different is known as a copolymer. For example, in Nylon-66 the monomers are adipic acid and hexamethylenediamine.

Question 4.
How do you explain the functionality of a monomer?
Answer:
The functionality of a monomer is the number of binding sites that is/are present in that monomer.
For example, the functionality of monomers such as ethene and propene is one and that of 1, 3-butadiene, and adipic acid is two.

Question 5.
Define the term polymerisation. (C.B.S.E. Delhi 2008)
Answer:
A very widely used polymer is polyethylene which is formed by the polymerisation of ethylene molecules (monomers) by heating under pressure in the presence of oxygen.

It may be noted that all the monomer units in a polymer may or may not be the same, In case, they are the same as in case of polyethylene, then the polymer is called homopolymer. On the other hand, if they happen to be different, then the polymer is known as copolymer or mixed polymer. For example, the monomer units in terylene are ethylene glycol and terephthalic acid. Similarly, hexamethylenediamine and adipic acid are the monomer units of nylon-66. Both are co-polymers or mixed polymers. We shall discuss these at a later stage in the present unit.

Question 6.

Answer:
It is a homopolymer in nature. It has only one type of monomer units i.e., NH₂ – CHR – COOH. These area-amino acids.

Question 7:
In which classes, are the polymers classified on the basis of molecular forces?
Answer:
Polymers are classified into four classes on the basis of molecular forces. These are:
elastomers, fibres, thermoplastic polymers, and thermosetting polymers.

1. Elastomers: In these polymers, the intermolecular forces are the weakest. As a result, they can be readily stretched by applying small stress and regain their original shape when the stress is removed. The elasticity can be further increased by introducing some cross-links in the polymer chains. Natural rubber is the most popular example of elastomers. A few more examples are of: buna-S, buna-N and neoprene.

2. Fibres: Fibres represent a class of polymers which are thread-like and can be woven into fabrics in a number of ways. These are widely used for making clothes, nets, ropes, gauzes etc. Fibres possess high tensile strength because the chains possess strong intermolecular forces such as hydrogen bonding. These forces are also responsible for close packing of the chains. As a result, the fibres are crystalline in nature and have also sharp melting points. A few common polymers belonging to this class are nylon – 66, terylene and polyacrylonitrile etc.

3. Thermoplastics: These are linear polymers and have weak van der Waals forces acting in the various chains and are intermediate of the forces present in the elastomers and in the fibres. When heated, they melt and form a fluid which sets into a hard mass on cooling, Thus, they can be cast into different shapes by using suitable moulds. A few common examples are polyethylene and polystyrene polyvinyls etc. These can be used for making toys, buckets, telephone apparatus, television cabinets etc.

4. Thermosetting plastics: These are normally semifluid substances with low molecular masses. When heated, they become hard and infusible due to the cross-linking between the polymer chains. As a result, they also become three-dimensional in nature. They do not melt when heated. A few common thermosetting polymers are bakelite, melamine-formaldehyde, urea-formaldehyde and polyurethane etc.

Question 8:
How can you distinguish between addition and condensation polymerisation?
Answer:
In addition polymerization: The monomers are unsaturated in nature i.e., they have atleast one double or triple bond in their molecules. They represent the functionality of the monomers which combine with each other at these sites. The addition polymerisation is generally chain growth polymerisation in nature. For example, polythene, polystyrene, PVC, Teflon etc. are all formed as a result of additional polymerisation.

In condensation polymerization: The monomer units have specific functional groups present which represent their functionality. The monomers combine through these functional groups and the polymerisation is step growth polymerisation in nature. For example, terylene, nylon-6, nylon-66, bakelite etc. are all formed as a result of condensation polymerisation.

Question 9:
Explain the term co-polymerization and give two examples.
Answer:
Co-polymerisation is a process in which a mixture of more than one different monomeric units are allowed to polymerise. The copolymer thus formed contains multiple units of each monomer in the chain. The formation of buna-S copolymer in which the monomers are : buta-1, 3-diene, styrene and sodium is an example of co­polymerisation.
Another Example of co-polymer: Buna-S is a co-polymer of 1 : 3 – butadiene and styrene in the presence of sodium metal.

Thus, as a result of addition polymerisation, the double bonds change to single bonds. A large number of monomer units can be linked in this way.
The addition polymerisation is normally a chain reaction in which the chain is built up by the successive addition of the monomer units. It involves a number of intermediates such as free radicals, carbocations or carbanions. Let us illustrate the chain growth polymerisation based upon different mechanisms.

Question 10:
Write the free radical mechanism for the polymerisation of ethene.
Answer:
The polymerisation of ethene to polythene consists of heating or exposing to light a mixture of ethene with a small amount of benzoyl peroxide initiator The process starts with the addition of phenyl free radical formed by the peroxide to the ethene double bond thus regenerating a new and larger free radical. This step is called chain initiating step. As this radical reacts with another molecule of ethene, another bigger sized radical is formed. The repetition of this sequence with new and bigger radicals carries the reaction forward and the step is termed as chain propagating step. Ultimately; at some stage the product radical thus formed reacts with another radical to form the polymerised product. This step is called the chain terminating step. The sequence of steps may be depicted as follows :
Chain initiating steps:

Chain terminating step:
For termination of the long-chain, these radicals can combine in different ways to form polythene. One mode of termination of the chain is shown as under:

Question 11:
Define thermosetting and thermoplastic polymers with two examples of each.
Answer:
Thermoplastics are polymers which can be easily softened repeatedly on heating and hardened on cooling. Therefore, it can be used again and again. For example, polyethylene and polyvinyl chloride. Thermosetting polymers are those which undergo permanent change on heating. They become hard and infusible on heating and cannot be softened again. For example, Bakelite, and Melamine formaldehyde.

Question 12:
Write the monomers used for getting the following polymers :

1. Polyvinyl chloride
2. Teflon
3. Bakelite

Answer:

1. vinyl chloride
2. tetrafluoroethylene
3. phenol and formaldehyde.

Question 13:
Write the name and structure of one of the common initiators used in free radical addition polymerisation.
Answer:

Question 14:
How does the presence of double bonds in rubber molecules influence their structure and reactivity?
Answer:
Chemically natural rubber is polyisoprene in which monomer units are of isoprene i.e., 2-methyl-i, 3-butadiene. It is in fact, 1, 4 polymer in which monomers are linked through CH₂ groups located at 1.4 positions. The residual double bonds are located at C₂ and C₃ positions in the isoprene units. All the double bonds have cis configurations. Thus, natural rubber is cis polyisoprene.

The high elasticity of natural rubber is due to the absence of polar groups and the cis-configurations about double bonds do I not allow the polymer chains to come closer. Therefore, only weak van der Waals’ forces are present. Since the chains are not linear, they can be stretched just like springs and exhibit elastic properties.

Question 15:
Discuss the main purpose of vulcanisation of rubber.
Answer:
The main purpose of vulcanization of rubber is to improve the following draw-back of natural rubber:

• At high temperature (T >335K) natural rubber becomes soft.
• At low temperature (T< 283K) natural rubber becomes brittle.
• Natural rubber is soluble in non-polar solvents.
• It is non-resistant to attack by oxidizing agents.

Question 16:
What are the monomers repeating units of Nylon 6 and Nylon 66?
Answer:
The monomeric repeating unit of nylon 6 is [NH – (CH₂)₅ – CO], which is derived from caprolactam.
The monomeric repeating unit of nylon 6, 6 is [NH – (CH₂)₆ – NH – CO – (CH₂)₄ – CO], which is derived from hexamethylene diamine and adipic acid.

Question 17:
Write the names and structures of the monomers of the following polymers:
(i) Buna-S
(ii) Buna-N
(iii) Dacron
(iv) Neoprene (C.B.S.E. Delhi 2008)
Answer:

Question 18:
Identify the monomers in the following polymeric structures:

Answer:
(i) Decanedioic acid: HOOC(CH₂)₈COOH
Octamethylenediamine: H₂N(CH₂)₈NH₂

(ii)

Question 19:
How is dacron obtained from ethylene glycol and terephthalic acid?
Answer:

Question 20:
What is a biodegradable polymer? Give an example of an aliphatic biodegradable polyester.
Answer:
A polymer that can be decomposed by bacteria is called a biodegradable polymer. Poly – β- hydroxybutyrate – Co -β – hydroxy valerate (PHBV) is a biodegradable aliphatic polyester.

We hope the NCERT Solutions for Class 12 Chemistry Chapter 15 Polymers help you. If you have any query regarding NCERT Solutions for Class 12 Chemistry Chapter 15 Polymers, drop a comment below and we will get back to you at the earliest.

NCERT Solutions for Class 12 Biology Chapter 4 Reproductive Health

These Solutions are part of NCERT Solutions for Class 12 Biology. Here we have given NCERT Solutions for Class 12 Biology Chapter 4 Reproductive Health

Question 1.
What do you think is the significance of reproductive health in a society?
Solution:
Significance of reproductive health in society are:

• Control over the transmission of STDs.
• Less death due to reproduction-related diseases like-AIDS, cancer of the reproductive tract.
• Control in a population explosion.
• Not only the reproductive health of men and women affects the health of the next generation.

Question 2.
Suggest the aspects of reproductive health which need to be given special attention in the present scenario.
Solution:
Providing medical facilities and care to the problems like menstrual irregularities, pregnancy related aspects, delivery, medical termination of pregnancy, STDs, birth control, infertility. Post-natal child maternal management is another important aspect of the reproductive and child health care programme.

Question 3.
Is sex education necessary in schools? Why?
Solution:
Yes, sex education is necessary for schools because:

• It will provide proper information about reproductive organs, adolescence, safe, hygienic sexual practices, and Sexually Transmitted Diseases (STDs).
• It will provide the right information to avoid myths and misconceptions about sex-related queries.

Question 4.
Do you think that reproductive health in our country has improved in the past 50 years? If yes, mention some such areas of improvement.
Solution:
The reproductive health in our country has improved in the last 50 years. Some areas of improvement are :

• Massive child immunization.
• Increasing use of contraceptives.
• Better awareness about sex related matters.
• Increased number of medically assisted deliveries and better post-natal care leading to decreased maternal and infant mortality rates.
• Increased number of couples with small families.
• Better detection and cure of STDs and overall increased medical facilities for all sex related problems.

Question 5.
What are the suggested reasons for the population explosion?
Solution:

• Improved medical facilities
• Decline in death rate, IMR, MMR
• Slower decline in birth rate.
• Longer life span.
• Lack of 100% family planning and education among the village.

Question 6.
Is the use of contraceptives justified? Give reasons.
Solution:
Yes, the use of contraceptives is justified: To overcome the population growth rate, contraceptive methods are used. It will help in bringing birth rate down & subsequently curb population growth. With the rapid spread of HIV/ AIDS in the country, there is now a growing realization about the need to know about contraception & condoms.

Question 7.
Removal of gonads cannot be considered as a contraceptive option. Why?
Solution:
Removal of gonads not only stops the production of gametes but will also stop the secretions of various important hormones, which are important for bodily functions. This method is irreversible and thus, can not be considered as a contraceptive method.

Question 8.
Amniocentesis for sex determination is banned in our country. Is this ban necessary? Comment.
Solution:
Amniocentesis is a prenatal diagnostic technique to find out the genetic disorders and metabolic disorders of the foetus. Unfortunately, the useful technique of amnio-centesis had been misused to kill the normal female foetuses as it could help detect the sex of foetus also. Hence, this technique is now banned in our country. This ban is necessary as this technique was promoting female foeticide in our country.

Question 9.
Suggest some methods to assist infertile couples to have children.
Solution:
If the couples are enabled birth to the children and corrections are not possible, the couples could be assisted to have children through certain special techniques, commonly known as Assisted Reproductive Technologies (ART). Some methods are given as:

1. In Vitro Fertilization (IVF): In this method, ova from the female and the sperm from the male are collected and induced to form a zygote under simulated conditions in the laboratory. This process is called In Vitro Fertilization (IVF). Some method is given as follows:

• Zygote Intrafallopian Transfer (ZIFT): The zygote or early embryo with up to 8 blastomeres is transferred into the fallopian tube.
• Intra-Uterine Transfer (IUT): Embryo with more than 8 blastomeres is transferred into the uterus in females who cannot conceive embryos formed by the fusion of gametes in another female are transferred.
• Test tube baby: In this method, ova from the donor (female) and sperm from the donor (male) are collected and are induced to form a zygote under simulated conditions in the laboratory. The zygote could then be transferred into the fallopian tube and embryos transferred into the uterus, to complete its further development. The child born from this method is called a test-tube baby.

2. Gamete Intra Fallopian Transfer (GIFT): It is the transfer of an ovum collected from a donor into the fallopian tube 8 another female who cannot produce one, but can provide a suitable environment for fertilization and further development of the embryo.

3. Intra Cytoplasmic Sperm Injection (ICSI) : It is a procedure to form an embryo HI* the laboratory by directly injecting the sperm into an ovum.

4. Artificial Insemination (AI): In this method, the semen collected either from the husband or a healthy donor is artificially introduced into the vegina or into the uterus (Intra Uterine Insemination, IUI). This technique is used in cases where the male is unable to inseminate sperms in the female reproductive tract or due to very low sperm counts in the ejaculation.

5. Host Mothering: In this process, the embryo is transferred from the biological mother to a surrogate mother. The embryo then develops till it is fully developed or partially developed. It is then transferred to the biological mother or into any other. This technique is useful for females in which embryo forms but is not able to develop.

Question 10.
What are the measures one has to take to prevent contracting STDs?
Solution:
Diseases or infections which are transmitted through sexual intercourse are collectively called sexually transmitted diseases (STDs) or reproductive tract infections (RT), e.g., gonorrhea, syphilis, genital herpes, AIDS, etc. The measures that one has to take to prevent from contracting STDs are:

• Avoid sex with unknown partners/multiple partners.
• use condoms during coitus.
• In case of doubt, go to a qualified doctor for early detection and get complete treatment if diagnosed with the disease.

Question 11.
State True/False with an explanation.

1. Abortions could happen spontaneously too.
2. Infertility is defined as the inability to produce viable offspring and is always due to abnormalities/defects in the female partner.
3. Complete lactation could help as a natural method of contraception.
4. Creating awareness about sex related aspects is an effective method to improve the reproductive health of people.

Solution:

1. True: One-third of all pregnancies abort spontaneously (called miscarriage) within four weeks of conception and abortion passes unrecognized with menses.
2. False: Infertility is defined as the inability of the couple to produce viable offspring. It is due to abnormalities/defects in either male or female or both.
3. True: Complete lactation is a natural method of contraception as during this period ovulation does not occur, but this is limited to a period of 6 months after parturition.
4. True: Creating awareness in people about sex-related aspects like right information about reproductive organs, accessory organs of reproduction, safe and hygienic sexual practices, birth control methods, care of pregnant women, post-natal care of mother and child, etc., can help in improving the reproductive health of people.

Question 12.
State True/False with an explanation.
(a) Abortions could happen spontaneously too. (True/False)
Answer:
False, Abortion does not happen under normal conditions. It happens accidentally or under the will of Parents.

(b) Infertility is defined as the inability to produce a viable offspring and is always due to abnormalities/defects in the female partner. (True/False)
Answer:
False, Sterility always does not occur due to females sometimes. Males are also responsible for this.

(c) Complete lactation could help as a natural method of contraception. (True/False)
Answer:
True, the Menstrual cycle does not occur after parturition which can act as natural
contraception but this method is functional for a period of six months from parturition.

(d) Creating awareness about sex related aspects is an effective method to improve the reproductive health of dead people. (True/False)
Answer:
True, this creates better reproductive health among people.

We hope the NCERT Solutions for Class 12 Biology Chapter 4 Reproductive Health help you. If you have any query regarding NCERT Solutions for Class 12 Biology Chapter 4 Reproductive Health, drop a comment below and we will get back to you at the earliest.