Explore topic-wise InterviewSolutions in .

Value Points :

• Anne changed in many ways over the two years she was writing her diary. Some of these changes can be described as “growth” 

• “She became an astute observer of politics, and of human nature, and she became a very practised and welleducated writer.”

• Many of her diary entries suggest a mind mature past her years, and we forget we are reading the work of a teenager.

• On one hand, she feels like she is still the exuberant and sociable person that made her so popular in school, but on the other hand, she feels like a persons with deep views and insights into the world around.

Detailed Answer :

By the time Anne started writing her diary she was just a thirteen-year-old teenager, who was a sufferer in the Second World War. She had to remain hidden in an annexe for 2 years. Within that time she underwent many changes. The major change described was “growth”. She became an astute observer of politics and human nature, and she became a very practised and well educated writer. Many of her diary entries suggest a mind mature past her years, as we forget that we are reading the work of a teenager. On one hand she feels like she is still the exuberant and soluble person that made her so popular in school, but on the other hand, she feels like a person with deep views and insights into the world around.

Value Points :

• The sisters were very different from each other

• Her sister was liked by mother and was closer to her

• Anne resented her

• She was difficult to understand and get along with

• Argumentative 

Detailed Answer :

Anne had an elder sister, Margot. Anne felt that her mother loved Margot more because she was well-mannered and studious. In fact the sisters were very different from each other and Anne resented her mother’s favourable attitude towards Margot. There grew a communication gap among the family members. Anne grew tired of her parents’ nosey attitude also. She felt that they never gave a satisfactory response. Whenever she approached them, they used to put her off. She had gradually turned into a girl who was difficult to understand and get along with. She became argumentative also. It was so specially in the case she found her mother favouring Margot. The harmonious relationship in the family was shattered. Anne used to have arguments with others like for example with Mr. van Daan, and with Mr. Dussel the dentist also. She found it difficult to get along well with her sister, mother and the other fellow residents of the annexe

B) Martin Luther Nails 95 Theses

Value Points :

• Anne not happy with the attitude of the grown-ups in the annexe.

• Whenever she approached them, they put her off. 

• never got a satisfactory response from them.

• felt that her mother lacked motherly feelings – never understood her.

• the grown-ups never allowed the children to form opinions of their own.

• children not given love and care.

• Anne felt elders should respect their opinions.

Detailed Answer :

Anne continued to get frustrated with the adults in the annexe. She was not happy with the attitude of the adults in the annexe. Whenever she approached them, they put her off and she was unable to get any satisfactory response from them. Anne was tired of her parents, interfering and nosey attitude. It was no longer a close and harmonious family which it used to be when they were at their own home. Anne felt neither respect nor admiration for mother. She just loved and admired one person and that was Peter. She found him to be decent and clever. Anne was of the opinion that parents should discuss sex and marriage with their children. They should not leave them on their own to find out the details. She even felt that her mother lacked motherly feelings. She never understood her. The grown-ups never allowed the children to form opinions of their own. They were not given love and care. They were not allowed to form their own opinions.

The conditions in the outside world were terrible. Burglaries, break-ins and thefts were very common. People were falling ill but the doctors could not attend them because their vehicles used to get stolen the moment they turned their backs. Scarcity of food made people stand in long queues for vegetables and other kinds of goods. Little children used to break the windows and steal anything they could lay their hands on. As far as clothing was concerned, people were wearing torn and worn out clothes. They didn’t have any proper clothes. The men were being shipped off to Germany and the children were undernourished or sick as they didn’t get proper food. There was an increase in the acts of sabotage against the authorities.

Value points :

Diary of a Young Girl - Character Traits of Anne Frank :

• Lovable, optimistic and typical adolescent

• Tries to make the best use of any situation 

• Though not close of her mother, got along well with her father-found solace in him

• Emotional – sensitive – relationship with Peter

• Expressed her feelings to ‘Kitty’, her diary.

Detailed Answer :

Anne was a lovable and optimistic girl. She is the represented up of all adolescent girls who always try to make the bust use of any situation. She was a good reader. In hiding she kept reading something or the other very day to continue her studies. She translated chapters, wrote down the vocabulary words and used to work hard. She enjoyed shorthand but later left it as her eyesight grew weak and she could not visit an ophthalmologist as long as she was in hiding in the secret annexe. She wanted to become a journalist. Like any other child, she loved her parents but later developed a dislike for the mother as she used to compare her to Margot, her elder sister whom she felt jealous of. She always had a feeling that her father loved her more than her mother. She found solace in him. She was emotional girl who suffered though out her life. Due to resistiveness, she developed a relationship towards peter but her parents did not approve it.

Anne’s relationship with her mother was of a complex and complicated nature. The complexities arose from the difference in disposition and temperament between the two and the complications stemmed from these complexities. Anne felt that she did not fit in with them, she saw her mother as being very sentimental and putting up a picture of a family that got along well together without taking into account individual feelings which might be different from the one that she imposed upon them. She felt detached from her; there was a gap in understanding between the two. She did not get along with her mother and felt alienated from her, their fractious relationship notwithstanding, Anne’s mother would fiercely defend her daughter if anybody raised a finger against her. Sometimes Anne couldn’t stand her mother because she thought that her mother was not interested in what went on in her daughter’s mind and Anne felt that she knew her girlfriends better than her mother. Anne believed that her mother, in spite of being well-educated, did not know much about the world and did not care to either. Anne was an independent spirit and could function in life without her mother’s support. We can look at it this way that her mother somewhat knew about this and in order to retain the parent child relationship, she treated Anne like a child because it is hard for a parent to come to terms with a child who doesn’t need a parent to live life, who is capable of taking care of herself without being nurtured by her parents. But every child needs their parent no matter how strong and capable they are, so her mother did not understand that and continued to follow the parents’ template of behaviour. Fact of the matter is, every child is different and there are no rules when it comes to bringing up a child. So, there seems to have been a gap in communication from both sides and this led to a difference of understanding between mother and daughter. However, as Anne grows up, she forgives her mother for her failures and decides to be more considerate towards her.

Anne Frank’s diary is considered to be a historical record because neither is it fiction nor has it been composed after the incidents took place. It is the diary of someone who lived the history of the Second World War. She was an eye witness to the Holocaust, and she recorded her firsthand experiences from a personal, political and social aspect. This record made by an ordinary citizen became a historical document because it was not a conscious project to document history taken up by a scholar. Rather it recounts the lived experiences of a young girl, living through the horrors of war and persecution on the grounds of ethnicity. As Anne didn’t share her feelings with anyone, she recorded them in her diary as if she were confiding to her diary named Kitty as it comforted her. She maintained it from June 12th, 1942 to August 1, 1944. Initially, she only wrote about herself but later on she edited her diary for posterity after hearing a March 1944 radio broadcast from an exiled Dutch government official who urged the Dutch people to keep journals and letters that would help provide a record of what life was like under the Nazis.

The diary was considered to be authentic because Miep Gies had recovered five notebooks and some 300 loose papers containing Anne’s writings from the Secret Annex shortly after the Frank’s arrest by the Nazis. He had hidden them in her desk and gave it to Otto Frank, the only survivor of the family, on his release from Auschwitz, who got the diary published.

Value Points :

• Miss Sullivan gave Helen a new doll.
• She spelled the word ‘doll’ into her hand – thus giving the object a name
• In order to make her realise that the word ‘doll’ applied to both dolls, she gave her the big rag doll.
• Impatient at the persistent attempts, Helen dashed the doll to the floor.
• She felt neither sorrow nor regret.
• Miss Sullivan swept away the fragments. 
• Went outdoors – returned - remembered the doll she had broken
• Tried to put it back together – repentance and sorrow

Detailed Answer : Miss Sullivan filled Helen’s life with confidence and joy. She kept on teaching her something or the other. Her next chapter was nature. She took her to the fields, and to the banks of the Tennessee River to learn about nature. Helen started enjoying the world she live in. Miss Sullivan made her feel the beauty in the woods, blades of grass, birds, flowers, in fact almost everything. But one stormy day gave Helen a feeling that nature can be cruel also. She was sitting on the branch of a tree and Miss Sullivan went home to bring lunch. Helen was left alone there. Suddenly, Helen felt the heat of the sun lessening and a terrible shaking of the trees. she grew frightened and longed for her teacher’s arrival. The feeling of terror kept on increasing and she made up her mind to jump down. Suddenly her teacher seized her hand and helped her down. The experience shook Helen terribly. it took her a long time to gather enough courage to climb another tree. But finally she climbed the mimosa tree which had large branches and rough barks. The feeling of having done something wonderful and unusual filled Helen’s mind. she felt like a fairy on a rosy cloud and spent many happy hours in the tree.

Value Points :

• thought she had a confused personality / her attitude / feelings towards Peter changed often.

• was cheerful, full of joy and had a great sense of humour.

• She cracked jokes and displayed affection. • the other side, hidden – more serious – sometimes moody.

• unable to confide in anyone – sometimes utter despondence engulfed her.

• fickle minded.

• She shared a love – hate relation with her mother, mostly hate.

• varied emotions in respect of Peter.

Detailed Answer :

Anne believed that her personality was split into two. One side contained her exuberant cheerfulness, her flippancy, the joy in her life and above all, her great sense of humour. She cracked jokes and displayed affection. This side would lead her to appreciate flirtations, a kiss, an embrace and even off-colour jokes. She was only a thirteen year- old girl. She was a young and innocent girl, who was discovering the appeal of being a young girl at this age. She was quite curious about the physical and emotional changes taking place in her but was too shy to ask anyone about them. The other side of her was hidden,purer, deeper and finer. She was unable to confide in anyone. She felt all alone in the presence of others. She was fickle minded. She had mixed love and hate emotions for her mother, mostly hated. She always had a feeling that her mother liked Margot more than her. With the result she used to hurt her mother’s feeling deliberately and didn’t even bother to apologize. But sometimes she used to feel bad about her attitude towards her mother. She had varied emotions for Peter as well she found herself to be in love in with him, but, was scared of her father’s scoldings also.

Value Points :

Kept herself busy in some activity or the other. Besides doing household chores - read books, translated a book, wrote down vocabulary words, translated French grammar, worked on shorthand and wrote diary.

Detailed Answer :

After going into the hiding in the secret annexe, Anne and her family faced a lot of problems. They were completely cut-off from the outer world. They had no means of recreation or entertainment and felt the days to be too long. Anne didn’t like this monotonous life. She kept herself busy in some activity or the other. She used to help her mother in her household chores. Besides doing that, she read many books which were supplied to them by their friends Jan, Miep and Bep She translated a book in French grammar. She worked at shorthand as well and wrote her diary also. They had to economize the usage of electricity so after it was too dark, Anne sometimes joined the other people in Annexe in their crazy activities like telling riddles, doing calisthenics in the dark, speaking English or French, reviewing books etc. But all these activities also got boring. So they discovered a new pasttime. They started using a good pair of binoculars to peek into the lighted rooms of the neighbors. So, life kept on moving for all of them, ever though at a slow pace.

The conditions in the outside world were terrible. Burglaries, break-ins and thefts were very common. People were falling ill but the doctors could not attend them because their vehicles used to get stolen the moment they turned their backs. Scarcity of food made people stand in long queues for vegetables and other kinds of goods. Little children used to break the windows and steal anything they could lay their hands on. As far as clothing was concerned, people were wearing torn and worn out clothes. They didn’t have any proper clothes. The men were being shipped off to Germany and the children were undernourished or sick as they didn’t get proper food. There was an increase in the acts of sabotage against the authorities.

Margot and Anne both had become tired of their parents in spite of the fact that they still loved them. They wanted to make their own decisions without being chaperoned by their parents. Their parents were not so strict and let them read everything, but Margot and Anne were sick and tired of having to listen to their comments all day long. The customary ritual of giving them little kisses at all hours of the day was also quite tiresome to these girls, who were almost in the throes of adulthood. The cute nicknames seemed affected. They would have liked nothing better than to get a break from their parents. Margot and Anne did not talk about all this to their parents because they felt that their parents would fail to understand. These young women were growing up with their own set of opinions, ideals and principles. Therefore, they wanted their parents to acknowledge their maturity and independence of spirit, taking them as young adults rather than children.

Value Points :

• acute congestion of the stomach and brain 
• doctors thought she would not live 
• fever was over, but she was blind and deaf for life 
• light became dimmer by the day
• she got used to the silence and darkness

Detailed Answer :

Helen was an eager and assertive child during her childhood. The beginning of her life was simple and much like every other little life. She received all privileges as the first baby in the family does. She was having a wonderful time as a baby but the ‘happy days did not last long’. In the month of February, she fell ill. The doctors called it an ‘acute congestion of the stomach and brain’. They thought that she would not live. However, one day the fever left her as suddenly and mysteriously as it had come. Everyone rejoiced on her becoming well. After getting well, she could feel her eyes turning dry and hot. Gradually, the light became dimmer by the day. It was like a nightmare as she turned blind and deaf for life. Not even the doctors realised that she would never see or hear again. It was terrible but with the passage of time she got used to the silence and darkness that surrounded her and forgot that life had, at some stage, been different and wonderful.

Value points :

Mr. Gilman

• Principal of Cambridge School for Young Ladies

• A sincere and caring educationist

• Gave special attention of Helen Keller – knew manual alphabets – read books with her.

• Had a broad view of history and literature – taught Helen English literature – made Helen’s work easier.

• Helped Helen with her German paper

• Concerned about Helen’s deteriorating health – made changes in her studies – not taken positively by Helen and her family.

Detailed Answer :

Mr. Gilman was the Principal of the Cambridge School for young ladies. When Helen took admission in this school, he was very sympathetic towards her. He was a sincere and caring educationist. He gave special attention to Helen Keller. He was well versed in the manual alphabets. He used to give her company during her reading. He even learnt the finger alphabet so as to enable himself to instruct Helen. He taught English literature and History to Helen and she also found her work easier and pleasant when she was instructed by Mr. Gilman. He was quite affectionate and caring towards Helen and gave admission to her sister Mildred in his school so that Helen could get some inspiration from her. He helped Helen with her German paper. Despite all this, he was a bit stern and rigid. When he felt that Helen was overworked and stressed, he decided that she should spend more years to complete her studies. However, Helen did not like this idea and withdrew herself from the school with the help of her mother.

Value points :

Mr. Gilman

• Principal of Cambridge School for Young Ladies

• A sincere and caring educationist

• Gave special attention of Helen Keller – knew manual alphabets – read books with her.

• Had a broad view of history and literature – taught Helen English literature – made Helen’s work easier.

• Helped Helen with her German paper

• Concerned about Helen’s deteriorating health – made changes in her studies – not taken positively by Helen and her family.

Detailed Answer :

Mr. Gilman was the Principal of the Cambridge School for young ladies. When Helen took admission in this school, he was very sympathetic towards her. He was a sincere and caring educationist. He gave special attention to Helen Keller. He was well versed in the manual alphabets. He used to give her company during her reading. He even learnt the finger alphabet so as to enable himself to instruct Helen. He taught English literature and History to Helen and she also found her work easier and pleasant when she was instructed by Mr. Gilman. He was quite affectionate and caring towards Helen and gave admission to her sister Mildred in his school so that Helen could get some inspiration from her. He helped Helen with her German paper. Despite all this, he was a bit stern and rigid. When he felt that Helen was overworked and stressed, he decided that she should spend more years to complete her studies. However, Helen did not like this idea and withdrew herself from the school with the help of her mother.

It was in the spring of 1890 that Helen Keller learned to speak. The impulse to utter audible sounds had always been strong within her. She used to make noises. She kept one hand on her throat while the other hand felt the movements of her lips. She was pleased with anything that made a noise. It was her urge to feel the cat purr and the dog bark. She was entirely dependent on the manual alphabet. But she was determined to use her lips and voice. Friends discouraged her. But the story of Ragnhild Kaata inspired her to succeed. In 1890, Mrs. Lamson returned from Norway and came to see Helen Keller. She told her of a deaf and blind girl named Ragnhild Kaata. Mrs. Lamson had taught her to speak. Helen resolved that she too would learn to speak. Miss Sullivan took Helen to Miss Sarah Fuller. She offered to teach her herself. Miss Fuller passed Helen’s hand over her face and let her feel the position of her tongue and lips when she made a sound. She was eager to imitate every motion and in an hour had learned six elements of speech: M, P, A, S, T, I. Miss Fuller gave eleven lessons in all. She was filled with delight and surprise when she uttered her first connected sentence. She uttered ‘‘It is warm.’’ They were broken and stammering syllables. But they were parts of a human speech. Miss Sullivan’s untiring patience and devotion helped her to progress towards natural speech.

Helen had leant to speak. At last, the happiest moment of her life arrived. The train stopped at the Tuscumbia station. The whole family stood at the platform. Her mother pressed her close to her trembling with delight. Every syllable that Helen uttered delighted her. The little Mildred seized, kissed her hand and danced. Seeing his daughter uttering audible sentences, he expressed his pride and affection in a big silence.

Helen Keller had a passion for books. She started reading when she was just seven years old. From that age she had constantly ‘devoured’ every printed page that came within her reach. She didn’t study regularly nor according to rule. At first she read a few books like ‘Our World’ in raised print. She preferred reading herself to being read to. She began to read in good earnest during her first visit to Boston. She wandered from bookcase to bookcase in the library to pick up books of her choice. The words themselves fascinated her. Her true interest in books started from ‘Little Lord Fauntleroy’. Then she read ‘Greek Heroes’, ‘‘Fables’’, ‘‘Bible stories’’, Lamb’s ‘Tales from Shakesperare’, ‘The Arabian Nights’, ‘The Pilgrim’s Progress’, ‘Robinson Crusoe’, ‘Little Women’ and ‘Heidi’. The stories in which animals were made to talk like human beings never appealed to her. But she loved ‘The Jungle Book’ and ‘Wild Animals’ because they were real animals and not caricatures of men. She loved antiquity and ancient Greece with pagan gods and goddesses fascinated her. Greek poetry suited her responsive heart. Her admiration for ‘The Aenid’ was not so great as for Homer’s ‘Iliad’. The stories of the Greeks were full of charm for her and the stories of the Bible didn’t interest her so much. Shylock and Satan were her favourite characters. Next to poetry she loved history. Her favourites were: Green’s ‘History of English People’, Freeman’s ‘History of Europe’ and Swinton’s ‘World History’. She loved to read German literature for its strength, beauty and truth. Goethe’s ‘Faust’ fascinated her. Of all the French writers she loved to read Moliere and Racine best. She loved to read Mark Twain and Scott. In a word, literature was her ‘utopia’. No barriers of senses could shut her out from the sweet and gracious discourse of her book-friends.

The path to get admission in Radcliffe College was marked with unimaginable difficulties. But it was the desire Helen harboured and her determination to be successful, despite the odds that helped her to overcome all the obstacles. She faced unexpected difficulties, from not having books embossed in time to begin her classes, lack of apparatus for some of her studies, to the problems related to special instructions in the classroom. Many a time even Miss Sullivan fell short of helping her with all the resources required for her preparation. At times this made Helen lose her courage but she did not lose her determination and each time moved on ahead with renewed confidence. Her faith and spirit combined with her determination helped Helen to get admission to Radcliffe College.

Helen Keller joined the Wright-Humason School for the Deaf in New York City in October 1894. The school was famous for its specialised training in vocal culture and lip-reading. Helen joined the school to improve her speech further. Besides learning speech, during two years she studied there arithmetic, physical geography, French and German. 

Helen made much progress in German because Miss Reamy, her German teacher, could use the manual alphabet. In a few months she was able to understand almost everything her teacher said. She found French much more difficult because Madame Olivier, a French lady, did not know the manual alphabet. So she could not read her lips easily. 

Helen’s progress in lip-reading and speech was unexpectedly slow. It was so because her ambition was to speak like other people, which was too high to achieve. So the disappointment was inevitable. No doubt, she worked very hard but found goal not within reach. She was not good at arithmetic. However, physical geography enabled her to learn the secrets of nature. All the teachers at the Wright-Humason School tried their level best to provide every advantage to the pupils of the school. So Helen looked back at the two years she spent there with fondness.

(i) (a) point sources (b) non–print sources. 

(ii) Easily identified source or place of pollution is called point source e.g. municipal, industrial discharge pipe etc. 

(iii) Agricultural run off, acid rain.

Hint: 

Reduce – While brushing your teeth, bathing etc.. we should not keep our taps on. 

Reuse – Water used for washing vegetables, rice etc. can be used for gardening. 

Recycle – Dirty water can be recycled after purification.

Pollution is not a distant phenomenon anymore. It is affecting the quality of our day to day lives. 

We must realize our responsibility and should start using the following environment- friendly processes:

1. We should switch to cleaner fuels like CNG- Compressed natural gas and LPG- Liquified petroleum gas for both industries and automobiles. 

2. Automobiles should also use unleaded petrol. 

3. We should plant more trees which will help to control deforestation. 

4. Industrial waste should be treated for harmful chemicals before discharging into air the water bodies. 

5. We must switch to alternative fuels instead of fossil fuels. Alternative sources of energy can be solar energy, hydropower and wind energy. 

6. We must encourage the use a public transport, a bicycle or walking for short distances. This will help to reduce the use of fossil fuels. 

7. Burning of plant waste also causes pollution by the emission of smoke. Plant waste must be put in a compost rather than burning.

(a) unwanted, harmful, living, non-living, air pollution. 

(b) industries, air, refineries, gaseous, sulphur dioxide, nitrogen dioxide. 

(c) brushing, tap, litres 

(d) drinking, potable 

(e) microorganisms, dissolved.

(a) nitrogen, oxygen

(b) carbon monoxide, smoke

(c) Methane, greenhouse gases

(d) global warming

(e) sewage, polluted

Change in temperature from their established habitats affects the kinetics of the enzymes and through it the basal metabolism, activity and other physiological functions of the organism.

Statements (b) and (d) are correct statements. The correct form of statements (a), (c) and (e) are as follows- 

(a) We can survive for some time without food but we cannot survive even for a few minutes without air. 

(c) Carbon monoxide is produced by incomplete burning of fuels such as coal, petrol, diesel. 

(e) Water which is suitable for drinking is called potable water.

Stopping distance depends on the following factors: 

1. Condition of roads 

2. Weather 

3. The condition of types and breaks of the vehicle.

(d) swimming in the pond.

F – I car race tracks are specially designed, so that driver can control on distance, stopping distance and on reaction time.

We are given that 

Initial velocity (u) =O 

Acceleration (a) = 8 m/s² 

Time (t) = 15 sec 

s = ?

\(s=ut+\frac{54}{3} at^2\\0\times15+\frac{54}{3}\times8\times15\times15\\4\times15\times15=900m\)

In second situation, Total stopping distance = Reaction distance x following distance time

\(54=x \times3=>x=\frac{54}{3}=18m\)

In the third situation, Total stopping distance = 27 x 4 = 108 m 

On wet road, the reaction distance will increase.

(a)–(iii), (b)–(iv), (c)–(ii), (d)–(i)

(b) distillation

(a) The common name of such wastewater is Sewage. The harmful substances like sewage, toxic materials, silt etc., when gets mixed with water, causes water pollution.

(b) Sewage water contains bacteria, viruses, protozoa, fungi and parasites(worms) which may cause diseases like cholera, typhoid and jaundice. The bacteria present in the fecal matter of mammals are indicates the quality of water. If water has these bacteria, it means that it has been contaminated by fecal matter. If such water is used by us, it can cause various infections.

(c) Drinking river water contaminated with such wastewater can result into diseases such as Cholera, Typhoid, Diarrhea, Dysentery and Jaundice.

Momentum p = mu 

Rate of change of momentum i.e. p is the same for both truck as well as car =Ka Car will have more K.E and thus, suffer more damage.

Treads are made on the upper surface of the tyre, to increase the friction between road and tyres. Due to this, the vehicle does not slip.

(i) Prevents photosynthesis – (d) Dust in air Dust reduces the photosynthesis in plants due which causes a decrease in energy production in plants causing the plants to suffer.

(ii) Damage ozone layer – (e) CFCs Chlorofluorocarbons used in refrigerators, air conditioners and aerosol sprays are responsible to deplete the ozone layer in the atmosphere. Ozone layer protects us from harmful ultraviolet rays of the sun.

(iii) Produce acid rain – (j) Sulphur dioxide Sulphur dioxide and nitrogen dioxide which reacts with water vapors in the atmosphere to form sulphuric acid and nitric acid. These acids combine with rain and makes the rain water acidic. This is called Acid rain.

(iv) Kill fish by deoxygenating water – (b) Excess fertilizer in fields The fertilizers act as nutrients for the algae to grow. When these algae die, they act as a nutrient for decomposers like bacteria. As a result of this process, a lot of oxygen in the water gets used up and leads to the deficiency of Oxygen in the water. This may kill the aquatic organisms including fish.

(v) Causes water borne diseases – (a) Sewage dumped in river Sewage water contains bacteria, viruses, protozoa, fungi and parasites(worms) which may cause diseases like cholera, typhoid and jaundice.

(vi) Leads to global warming in air – (c) Carbon dioxide in air Carbon dioxide is the gas which is mainly responsible for causing global warming. Carbon dioxide traps heat and does not allow it to escape into space causing an increase in the average temperature of the earth’s atmosphere.

If the air in tyres is more than the fixed range then tyres burst out, due to large air pressure. On the other hand, if air pressure is low then the actual range than either the consumption of petrol/ diesel will be more, or there is a possibility of a puncture in the tube.

Yes high temperature can kill the germs. We can purify water by boiling but on the other hand hot water from power plants and industries released into rivers adversely affect the animals and plants living in it.

The prime reason for melting of Gangotri glacier is global warming which is caused by rapid increase in industrialization, burning of fossil fuels and deforestation. Global warming is increasing average temperature of earth gradually. Melting of glaciers is normal but it is due to this increase in temperature that glaciers are melting more than they actually should.

Fossil fuels burn in the air to produce gases such as Sulphur dioxide and nitrogen dioxide. Sulphur dioxide and nitrogen dioxide which reacts with water vapors in the atmosphere to form sulphuric acid and nitric acid. These acids combine with rain and makes the rain water acidic. This is called Acid rain. Acid rain caused by the burning of fossil fuels makes the lake water too much acidic which kills the fish.

The fertilizers act as nutrients for the algae to grow. When these algae die, they act as a nutrient for decomposers like bacteria. As a result of this process, a lot of oxygen in the water gets used up and leads to the deficiency of Oxygen in the water. This may kill the aquatic organisms including fish.

20 Hz to 20000 Hz.

Different treads produce a different type of friction and hence, helpful in preventing slipping of cars, during accidents.

After the collision of two vehicles, if they stick together, then according to the workenergy principle, kinetic energy is converted into heat energy’.

Water can be made potable at home by following ways:

•  Physical method: use of household filter like candle type filter
• Chemical method: adding of chlorine tablets or bleaching powder to water which is called chlorination process. We should not use more chlorine tablets than specified otherwise it may be harmful.
• We can also purify water by boiling at home.

(c) pure and fit for drinking.

With the help of stopwatch, one can count the seconds.