LIGHTENED TO LIGHT

  Chapter 13 Fun with Magnets 1.       It was observed that a pencil sharpener gets attracted by both the poles of a magnet although its body is made of plastic. Name a material that might have been used to make some part of it. Ans:   Iron is used to make some part of sharpener due to which it is attracted toward magnet. . 2.       Write any two properties of a magnet. Ans:   Two properties of magnets are: (i) A magnet has two poles: North pole and South pole. (ii) Like poles repel each other and unlike poles attract each other. 3.       Where are poles of a bar magnet located? Ans:  Poles are located at the ends of bar magnet just before the ends. These are north and south poles. 4.       A bar magnet has no markings to indicate its poles. How would you find out near which end is its north pole located? Ans:  Take the bar magnet and suspend it freely with the help of a thread, the end that points towards north pole will be regarded as north end of the magnet. Take a b

  Chapter 12 Electricity and Circuits 1. What is the purpose of using an electric switch? Name some electrical gadgets that have switches built into them. Ans:  Electric switch is used to make electric circuit open or closed for a particular appliance and hence with the help of a switch we can use an appliance according 2. Would the bulb glow after completing the circuit shown in Fig. 12.9 if instead of safety pin we use an eraser? Ans:  No, since eraser is an insulator so it does not allow the current to pass. Hence the bulb will not glow. 3. Using the“conduction tester” on an object it was found that the bulb begins to glow. Is that object a conductor or an insulator? Explain. Ans:  Yes, if the object is good conductor of electricity then current will pass through conduction tester and the bulb will glow. Hence the object will be a conductor of electricity. 4. Why should an electrician use rubber gloves while repairing an electric switch at your home? Explain. Ans:  Our

  Chapter 11 Light Shadows and Reflection   1.    In a completely dark room, if you hold up a mirror in front of you, will you see a reflection of yourself in the mirror? Ans:  No, in a completely dark room no image will be formed because there is no light in the room so no reflection of light takes place and no image will be formed. 2.   Whether the moon is luminous or non-luminous body? Ans:  Moon is non-luminous body. 3.   What is umbra? Ans:  Umbra is the dark region behind object facing light which does not receive light at all. 4.   How does a light ray travel? Ans:  Light ray travels in a straight line. 5.   Give one natural source of light.  Ans:  Sun is a natural source of light. 6.   What is shadow?  Ans:  Shadow is the dark space behind an opaque object where light does not reach. 7.   What is penumbra? Ans:  The less darker shadow formed penumbra.on the periphery of dark shadow is called penumbra. 8.    State difference between a luminous and a no

  LESSON 15   THE SOLAR SYSTEM AND THE EARTH   1.   What are stars? Why do they look small? A star is a huge ball of hot glowing gases. They are very big or huge but looks small because they are very very far from us.   2.   What does the solar system consist of? The word solar means the sun. the solar system consists of the sun, eight planets and their natural satellites, comets, meteors, asteroids, etc.   3.   What is a planet? The term planet means wanderer. A planet is a large circular object make of gas and rock that spins like a top as well as moves around the sun on a fixe path.   4.   What make Saturn look beautiful? Saturn has rings of gases, dust and rocks around it which make it look very beautiful.   5.   What are satellites? Satellites are small objects that revolve around the planets. They revolve around the planets in their fixed orbits.   6.   Why does life exist on earth? Earth is the only planet in the solar system that is known

LESSON – 12 THE TALE OF PETER RABBIT 1.   What were the names of Mrs. Rabbit’s children? Flopsy, Mopsy, Cottontail, and Peter were the names of Mrs Rabbit’s children.   2.   Where did the rabbits live? In a sandbank, underneath the root of a very big fir tree.   3.   What did Mrs. Rabbit tell the children to do? They could go into the fields but not to go into Mr McGregor’s garden.     4.   Where did Peter go? Peter went straight away into Mr McGregor’s garden.   5.   What did Peter get stuck in? Peter got stuck in a gooseberry net.  

  LESSON 19 SUN, MOON, SKY AND STARS 1.    Name the planets of the solar system. The eight planets are – Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.   2.    How does the night sky appear? a.    In summer season: - night sky is clear and we can see the moon and the stars.   b.    In monsoon: - at night the moon is hidden behind the clouds     3.    Why is there no life on moon? There is no air on the moon to breathe. So there is no life on it.   4.    What are stars? Why do they appear small? Stars are big balls of fire. The stars are very far away, so they appear to be very small.   5.    What are the three main seasons? The three main seasons are summer, winter and monsoon.

  LESSON 12 ARUN’S COMPUTER 1.   Where did Arun go one evening? Arun went to his room.   2.   What did he do in his room? . He did not put on the light; he switched on his computer.   3.   What noises did the computer make? Buzzz, tirp, plip, plip, plip……….. and Buzz breep, blick, karrr!   4.   What did Arun first see on the screen? Blue; then a face.   5.   What messages did Arun type? ‘HELLO. WHO ARE YOU?’   6.   Who was the boy on the screen? It was Arun (the reflection of Arun.)  

  LESSON – 11 CLEANLINESS I.                     EXPLAIN THE FOLLOWING TERMS:- 1.     Oral hygiene :- oral hygiene is cleaning the mouth and teeth. We should brush our teeth twice daily.   2.     Personal hygiene :- personal hygiene means to practise simple healthy habits of cleanliness and follow them regularly.   3.     Healthy food :- healthy food means eating a balanced diet including energy giving foods, body building foods etc.   4.     Swachch Bharat Abhiyan : - swachchh bharat abhiyan is the biggest cleanliness drive. It is also called clean India mission. Under this program many efforts are being made to make the country clean and make toilets available for all.   II.               ANSWER THE FOLLOWING QUESTIONS:-   1.     What is personal cleanliness? List two ways by which we can keep our bodies clean. To remain fit and fine, we need to clean our body. This is called personal cleanliness. The ways by which we can keep our bodies clean are: