Name the substance which is most non-conducting.
[5] Heat and Energy
Chapter: [5] Heat and Energy
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Is air a good conductor of heat?
[5] Heat and Energy
Chapter: [5] Heat and Energy
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Among solids ebonite and asbestos are the worst conductors of heat. Is it a correct statement?
[5] Heat and Energy
Chapter: [5] Heat and Energy
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Why are cooking utensils made of metals?
[5] Heat and Energy
Chapter: [5] Heat and Energy
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Why are hollow bricks used in the construction of cold storage rooms?
[5] Heat and Energy
Chapter: [5] Heat and Energy
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Name a liquid which is a good conductor of heat.
[5] Heat and Energy
Chapter: [5] Heat and Energy
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Arrange the following in order of increasing heat conductivity: copper, air water, mercury.
[5] Heat and Energy
Chapter: [5] Heat and Energy
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Explain the following:
In a solid, heat is not transferred by the process of convection.
[5] Heat and Energy
Chapter: [5] Heat and Energy
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Explain the following:
Conduction is not possible in vacuum.
[5] Heat and Energy
Chapter: [5] Heat and Energy
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Explain the following:
Why is the cooling in a refrigerator kept near the top?
[5] Heat and Energy
Chapter: [5] Heat and Energy
Concept: undefined >> undefined
Explain the following:
It is cool in the shade, when it is hot outside.
[5] Heat and Energy
Chapter: [5] Heat and Energy
Concept: undefined >> undefined
The following figure shows a rectangular box with two tubes P and Q at the top. A burning candle R is placed under the tube P. The candle burns brightly.
Explain:
(i) How is the air in the box circulating?
(ii) What will happen if the opening Q is closed?
[5] Heat and Energy
Chapter: [5] Heat and Energy
Concept: undefined >> undefined
The following figure shows a container in which a lighted candle has been kept. The container has two openings, p, and Q. Which way the smoke from an external source placed near P moves when it reaches P and leaves from Q. Give a reason for your answer.
[5] Heat and Energy
Chapter: [5] Heat and Energy
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Name the process by which we receive heat from the sun.
[5] Heat and Energy
Chapter: [5] Heat and Energy
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How can the radiating power of a surface be increased?
[5] Heat and Energy
Chapter: [5] Heat and Energy
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At what speed does the heat radiation travel? What path does it follow?
[5] Heat and Energy
Chapter: [5] Heat and Energy
Concept: undefined >> undefined
Draw a labeled diagram of a vacuum flask and explain how the heat transfer minimized in it.
[5] Heat and Energy
Chapter: [5] Heat and Energy
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What do you understand by an electric circuit?
[8.1] Electricity
Chapter: [8.1] Electricity
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Define displacement. State its unit.
[2] Motion in One Dimension
Chapter: [2] Motion in One Dimension
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Differentiate between distance and displacement.
[2] Motion in One Dimension
Chapter: [2] Motion in One Dimension
Concept: undefined >> undefined
