Tag: conduction

Questions Related to conduction

Substances which allow heat to pass through them are called:

  1. Conductors

  2. Insulators

  3. Moderators

  4. None of these


Correct Option: A
Explanation:

Conductors allow heat to pass through them through vibration of the molecules.

A coin is dipped in the molten wax in a glass tube. When we heat the upper part of the glass tube, the wax around the coil will not melt because:

  1. Wax has a very high melting point

  2. Wax is a good conductor of heat

  3. Glass is a good conductor of heat

  4. Wax or glass are bad conductors


Correct Option: D
Explanation:

Glass is a bad conductor of heat hence the heat from the upper part of the glass tube will not transfer easily to the lower part. Having said that, even wax is a bad conductor of heat and won't melt easily. 

Mercury is a good conductor of heat.State true or false.

  1. True

  2. False


Correct Option: A
Explanation:
Mercury is good conductor of heat. (True)
Thermal conductivity of mercury is $8.30W/mK$. This is the fact why it was used in classical, thermometers for measuring temperature.

The best conductor of heat is

  1. Silver

  2. Bronze

  3. Aluminium

  4. Copper


Correct Option: A
Explanation:

Silver is the best conductor of heat among the given options.

When you pour hot tea suddenly on to a glass tumbler, it cracks. Because:

  1. Glass cannot resist heat

  2. Glass expands unevenly around the place of contact with the tea

  3. Tea has chemicals which react with glass tumblers.

  4. The reason is yet to be discovered by the scientists.


Correct Option: B
Explanation:

When the hot tea is poured into the glass tumbler one side of the glass expands while the other side doesn't. Since glass is not a good conductor of heat, it breaks.

Cups are not made of metals. The reason is:

  1. Metals are good conductors

  2. Metals are bad conductors

  3. Metals are expensive

  4. None of the above


Correct Option: A
Explanation:

Metals are good conductors of heat hence a person might get his fingers injured if he holds the hot plate. 

Select the odd one out w.r.t. conduction of heat (gold, copper, mercury, cork)

  1. cork

  2. gold

  3. copper

  4. mercury


Correct Option: A
Explanation:

Cork is a bad conductor of heat rest are good conductors

Define insulator of heat.

  1. Substances through which heat can pass easily are called insulators of heat.

  2. Substances through which heat cannot pass easily are called insulators of heat.

  3. Substance which can easily freeze are called insulators of heat.

  4. Substances which cannot freeze easily are called insulators of heat.


Correct Option: B
Explanation:

Insulators are  through which heat cannot pass easily.

Select the odd one out w.r.t. conduction of heat (gold, silver, copper, asbestos)

  1. asbestos

  2. gold

  3. silver

  4. copper


Correct Option: A
Explanation:

Asbestos is an insulator rest are good conductors of heat

State whether given statement is True or False
Iron is a better conductor of heat than copper

  1. True

  2. False


Correct Option: B
Explanation:
Thermal conductivity is quantity of heat transmitted due to temperature gradient in unit time under steady conditions in a direction normal to surface of unit area.
Thermal conductivity of copper = 386
Thermal conductivity of iron at $68^oC$ is 73

Thermal conductivity of copper is greater than iron.