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prove by an experiment air is a bad conductor of heat

 Take an empty long test tube. Hold the test tube tilted with its mouth downwards. Heat the tube at its bottom on the flame of a candle. It is noticed that the fingers do not feel warm. This shows that th air trapped in test tube does not conduct heat from the heated bottom of the test tub to the fingers. This proves that air is a bad conductor of heat.

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Take an empty long test tube. Hold the test tube tilted with its mouth downwards. Heat the tube at its bottom on the flame of a candle. It is noticed that the fingers do not feel warm. This shows that th air trapped in test tube does not conduct heat from the heated bottom of the test tub to the fingers. This proves that air is a bad conductor of heat

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take a long test tube and keep your hands at one end 

then heat the test tube 

your fingers do not feel warm 

this shows that air is a bad conductor oh heat.

 

plaese give me thums up

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take a test tube and put in a piece of wax such that it drops to and stays at the bottom of the test tub.then cover the mouth of the test tube with a cork .now heat the test tube at its mouth.it is obs. that after some time the cork will blow off but the wax remains intact without melting.

This proves that air is a bad condustor of heat

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Air is a gas. It is not a good conductor of heat. It is an insulator. Open air molecules are far too disperse from one another to conduct heat efficiently. Heat is conducted by molecules and atoms that are very closely bonded together and vibrating at high frequencies. Open air is just not dense enough.

Take a small metal bowl and keep it over a gas or electric oven. Ignite the oven to heat up the bowl for some time , say 5 mts.. Then put off the oven and bring your fingers at the height of the brim of the bowl without touching the metal bowl. You may feel a little bit of heat but not much. Now place a metal cover on the bowl and heat up the bowl for exactly the same time as done earlier. Now touch the metal cover carefully ( your fingers may burn if the bowl gets heated up too much ) and you will feel that the cover is heated up much more that what you felt earlier. Explanation :- In the first occasion, the bowl was containing the air only and you felt much less heat at the height of the brim of the bowl. But on the second occasion since the metal cover was placed on the bowl thus forming a part of the metal bowl itself it has conducted heat much more than the earlier occasion. It proves that air is a poor conductor of heat 91st occasion) and metal is a good conductor of heat (2nd. occaion). This can be experienced better if you can place a thermometer or any tepmerature measuring device at the brim height of the bowl without touching it (1st. occasion) and on the metal cover (2nd. occasion).
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Take a hard glass teat tube and in it place a small piece of wax.Cork the mouth of test tube and clamp it in an iron stand.Heat the test tube near its mouth.It is observed that in a few minutes the cork blows off, but wax does not melt.

(this experiment is as given in icse physics)
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