# Heat

A
conduction
B
convection
C
D
condensation
Hard
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## A student took an iron rod and a wooden rod and wrapped each of them in a piece of paper. These were then heated as shown. It was found that the paper around the iron rod does not burn whereas the one around the wooden rod catches fire.It is because

A
Candle, in case of iron rod, is nearer to the paper
B
Wood being a bad conductor of heat, takes away all the heat
C
Iron being a good conductor of heat, conducts away the heat give to the paper
D
Paper, in first case, is thicker
Hard
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## Two thermometers are used to record the temperature of a room and the bulb of one is wrapped in a wet hanky.

A
The temperature recorded by both will be same
B
The temperature recorded by the wet-bulb thermometer will be greater than that recorded by the other
C
The temperature recorded by dry-bulb thermometer will be greater than that recorded by the other
D
None of the above
Hard
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## Boojho has three thermometers as shown in above Figure. He wants to measure the temperature of his body and that of boiling water. Which thermometer (s) should he choose?

A
Thermometer (i) or (iii) for measuring body temperature and (ii) for measuring the temperature of boiling water.
B
Thermometer (i) for measuring temperature of both.
C
Thermometer (ii) for measuring temperature of both.
D
Thermometer (iii) for measuring temperature of both.
Hard
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## A metal spoon is placed in one of two identical cups of hot coffee. Why does the cup with the spoon have a lower temperature after a few minutes ?

A
Energy is removed from the coffee mostly by conduction through the spoon.
B
Energy is removed from the coffee mostly' by convection through the spoon.
C
Energy is removed from the coffee mostly by radiation through the spoon.
D
None of these
Hard
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## Mercury is often used in clinical thermometers. Which one of the following properties of mercury is not a reason for this ?

A
The coefficient of the thermal expansion is large
B
It is shiny
C
It is a liquid at room temperature
D
It has high density.
Hard
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## Two thermometers are constructed in such a way that one has a spherical bulb and the other has elongated cylindrical bulb. The bulbs are made of same material and thickness. Then :

A
spherical bulb will respond more quickly to temperature changes
B
cylindrical bulb will respond more quickly to temperature changes.
C
both bulbs will respond same to temperature changes
D
none of both bulbs respond to temperature changes
Hard
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Assertion

Reason

## The heat loss is mainly due to radiation.

A
Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
B
Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
C
Assertion is correct but Reason is incorrect
D
Both Assertion and Reason are incorrect
Hard
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