Tag: conduction

Questions Related to conduction

Multiple choice physics transfer of heat heat and heat transfer heat energy transfer heat energy transfers fundamentals of heat transfer conduction

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

Reveal answer Fill a bubble to check yourself
D Correct answer
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. 

Multiple choice physics transfer of heat heat and heat transfer heat energy transfer heat energy transfers fundamentals of heat transfer conduction

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.

Reveal answer Fill a bubble to check yourself
B Correct answer
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.

Multiple choice physics transfer of heat heat and heat transfer heat energy transfer heat energy transfers fundamentals of heat transfer conduction

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.

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Insulators are  through which heat cannot pass easily.

Multiple choice physics transfer of heat heat and heat transfer heat energy transfer heat energy transfers fundamentals of heat transfer conduction

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

  1. True

  2. False

Reveal answer Fill a bubble to check yourself
B Correct answer
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.