Std 6 English Lesson 3.7 At the Science Fair – questions and answers.


1. Answer the following questions:

(a) What two basic rules were followed in the Science Fair?

Ans. The two basic rules that were followed in the Science Fair were:

(i) everything should be handled by students and two,

(ii) everything – even the entertainment booths and refreshment stalls – had to have a scientific base. 

(b) How early did the preparations for the Science Fair begin?

Ans. The preparations for the Science Fair began a couple of months in advance.

(c) How was the committee formed?

Ans. A committee of parents and teachers was set up to look after all the work of the fair. Some student representatives were also taken on the committee to give them a first hand experience of managing big programmes like this.

(d) What themes did the committee identify?

The themes identified by the committee were:

Plants, Animals, Properties of Substances, Energy (forms of energy and energy resources), Science in our Everyday Life, Latest News from the World of Science, and Food and Nutrition.

(e) How did the students prepare for their stalls/presentations?

Ans. The students prepared by collecting a lot of information about their topic using their science textbook, their school library and also the internet. They shared and discussed this information in their groups.

(f) What did Mr Gizare appreciate the most?

Ans. Mr Gizare appreciated the fact that in most of the stalls, visitors could also try out the various science experiments and models.

(g) What did the Clean Brigade do?

Ans. The brigade members made rounds of the Fair spreading the message of cleanliness. They were wellequipped with garbage cans, scoops, brooms and wipes.

2. Make charts to show the important points to remember while making –

(a) A graphic presentation

Ans text book page 76

(b) An oral presentation.

Ans. text book pages 76 -77

3. Relate the themes of the Fair to your science textbook by writing the relevant chapter numbers under each theme.


Theme Lesson no.
Plants Chapter 2, 3
Animals Chapter 2, 3
Properties of substances Chapter 5
Energy Chapter 11
Science in our everyday life. Chapter 6
Latest news from the world of science. Chapter 4
Food and Nutrition Chapter 7

4. Find, in your science textbook, the topics of the stalls handled by students of VI A. (Write the page number.)

Stall Lesson
Use of kinetic energy Chapter 11
Use of potential energy Chapter 11
Sound Chapter 13
Electrostatic energy Chapter 11
Food Adulteration Chapter 7
Fun with magnets Chapter 15
Maintaining machines Chapter 12

5. What themes would you like to add to the themes given in this passage?

Ans. Themes I would like to add are

(i) reduce, reuse, recycle

(ii) harmful effects of plastic

(iii) deforestation, industrialization & global warming

6. Imagine you are visiting the Science Fair. What other stalls (apart from the ones mentioned here) are you likely to find there? Try to list at least five more stalls.

Ans. (i) Alternative sources of energy

(ii) no to tobacco and drugs

(iii) saving water at home.

7. Using your imagination, and information from other sources, describe any one stall in detail.

Ans. Today I visited the science fair of my school. I was attracted to one particular stall and that was the stall depicting the Universe and the Solar system.

I have always been fascinated by the sky and all the celestial bodies. So I listened very attentively to the information that the students were explaining. The students had put up the information in a systematic manner in the form of posters. They had also made a 3 D model of our solar system.

But the high light of the event was, the students had invited Dr Swarup, a scientist from Nehru Planetarium, Mumbai. And he just walked into the stall and stood next to me. My happiness knew no bounds and I asked him a lot of questions, which he very patiently answered. He was also very impressed with all the questions I was putting. So he invited me to Mumbai and asked me to meet him at his office. He even gave me his visiting card, with a hand written note at the back, signed by him. I shall cherish this moment all my life and surely shall go to meet him during my next vacation.

8. Choose a ‘question’ through your own observation. Try to follow the scientific method to find the answer to that question. Take the help of your teacher/parents to set up the experiment.

Ans. How to make a solar cooker at home?

Steps to make a light weight solar cooker.

1. Place a cardboard box inside a larger cardboard box. Remove the tops of both boxes, and place the small one inside the larger one. Make sure there is at least a gap of 1 inch (2.5 cm) between the boxes. Glue the smaller cardboard box into place by squeezing glue onto the bottom and then pressing the smaller box firmly into the larger box.

2. Fill the gap between the boxes with shredded newspaper or torn fabric. Tear the newspaper or fabric into strips, crumple them, and stuff them into the gap between the two boxes. Make sure to entirely fill the gap so there is no empty space.

  • The paper or fabric will act as insulation, which keeps the heat trapped inside the oven.

3. Line the inside of the smaller box with black construction paper. Cut pieces of black construction paper that are the dimensions of the walls and bottom of your cardboard box. Use glue to paste them in.

  • Black absorbs heat very easily, so it will keep your oven toasty.

4. Cut trapezoids from cardboard. The narrow side of the trapezoid should be the same width as one side of your large box. This is the side you will attach to the box. The wide edge of the trapezoid should be 2 inches (5.1 cm) wider than the small edge.

  • Use a utility knife to cut the cardboard. Place your cardboard on a scratch-proof surface, like the garage floor to cut it. Always cut in the direction away from your body, to avoid accidentally cutting yourself.

5. Cover each square of cardboard with a reflective surface. You can use aluminium foil, mylar, a mirror, a metallic auto-shade, or another reflective surface. This will reflect the sun’s rays into the solar oven and heat up your food. Tape the foil or other material securely to the cardboard using duct tape or cement glue. Now that the cardboard is covered in foil it can act as a reflector.

  • If you’re using aluminium foil, smooth it out so that it has as few wrinkles as possible.

6. Attach each reflector to each of the top edges of the big box. Use duct tape to securely tape the each reflector to each side of the big outer box. Don’t worry that they flop over. You will prop them up.

7. Prop each reflector up at around a 45 degree angle. You can buy thin, sturdy metal rods at a hardware store. Stick the rods into the ground underneath the reflectors. Prop the reflectors on the rods, and glue them into place.

  • If you’re operating your solar oven on a windy day, take extra care that the rods don’t blow over by sticking them more deeply into the ground.

8. Position the oven in full sun, and put your pan of food inside. For best results, use your solar oven between 11am and 2pm. That’s when the sun is at its most intense. You can use your solar oven any season of the year, as long as its sunny out.

  • The sun moves throughout the day, so if you’re cooking something that’s going to take a few hours, make sure you don’t put the oven someplace that will be shady in an hour.

9. Wait a long time for your food to cook. Don’t be surprised when your food takes way longer to cook than it would in a conventional electric oven. A solar oven is at a much lower temperature, so it will slow-cook your food, kind of like using a crock pot. 

  • You may need to reposition your box several times during cooking to catch the sun.
  • Measure the internal temperature of your meat with a meat thermometer, which you can stick into whatever you’re cooking. Make sure meat gets up to at least 170 °F (77 °C), which is the temperature that kills germs.

9. Visit a library: Find and read the biography of your favourite scientist


Sir Chandrasekhara Venkata Raman (7 November 1888 – 21 November 1970) was an Indian physicist known mainly for his work in the field of light scattering. With his student K. S. Krishnan, he discovered that when light traverses a transparent material, some of the deflected light changes wavelength and amplitude. This phenomenon was a new type of scattering of light and was subsequently termed as the Raman effect (Raman scattering). Raman won the 1930 Nobel Prize in Physics and was the first Asian person to receive a Nobel Prize in any branch of science.

Born to Tamil parents, Raman was a precocious child, completing his secondary and higher secondary education from St Aloysius’ Anglo-Indian High School at the ages of 11 and 13, respectively. He topped the bachelor’s degree examination at the University of Madras with honours in physics from Presidency College at age 16. His first research paper, on diffraction of light, was published in 1906 while he was still a graduate student. The next year he obtained an M.A. degree. He was 19 years of age when he joined the Indian Finance Service in Calcutta as Assistant Accountant General. There he became acquainted with the Indian Association for the Cultivation of Science (IACS), the first research institute in India, which allowed him to do independent research and where he made his major contributions in acoustics and optics.

In 1917, he was appointed as the first Palit Professor of Physics by Ashutosh Mukherjee at the Rajabazar Science College under the University of Calcutta. On his first trip to Europe, seeing the Mediterranean Sea motivated him to identify the prevailing explanation for the blue colour of the sea at the time, namely reflected Rayleigh scattered light from the sky, as being incorrect. He founded the Indian Journal of Physics in 1926. He and Krishnan discovered on 28 February 1928 a novel phenomenon of light scattering, which they called “modified scattering,” but more famously known as the Raman effect. The day is celebrated by the Government of India as the National Science Day every year. Raman moved to the Indian Institute of Science in Bangalore in 1933 to become its first Indian Director. There he founded the Indian Academy of Sciences the same year. He established the Raman Research Institute in 1948 where he worked to his last days.

In 1954, the Government of India honoured him with the first Bharat Ratna, its highest civilian award. He later smashed the medallion in protest against Prime Minister Jawaharlal Nehru’s policies on scientific research.

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