Tag: transfer of heat

Quizzes (8) Questions (172)

Questions Related to transfer of heat

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

Which of the following is the very poor conductor of heat ?

  1. Water

  2. Metals

  3. Liquid other than water

  4. Steam
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Water is the poor conductor among all. As it is liquid and liquids generally have low heat conductivity than solids. Tighter the molecules are held, more the vibrational energy can transfer between them, heat is no more than vibrating molecules. If we talk about steam, its molecules are less tightly held. But it's important to note that we are talking here of heat conductivity not convection or radiation and contact surface area with heat source.

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

Assertion (A): Woolen clothes keep the body warm in winter
Reason (R): Air is bad conductor of heat

  1. Both A and R are true,

  2. Both A and R are false

  3. Both A and R are true, R is correct explanation of A

  4. Both A and R are true, R is not correct explanation of A
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Woollen clothes effectively separate the body from surrounding air by entrapping a layer of air.
Since both wool and air are bad conductors of heat on varying levels, it creates separation that keeps bodies warm.

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.