Physics · Science General

Heat Transfer Mechanisms

877 Questions

Heat Transfer Mechanisms deal with the movement of thermal energy through conduction, convection, and radiation. It involves practical applications like ocean heat storage and atmospheric heating. These fundamental physics concepts are frequently asked in general science sections.

Thermal conductionHeat convectionThermal radiationSpecific heatStates of matter

Heat Transfer Mechanisms Questions

Multiple choice

Match the following:

 
a. Conduction 1. It is the process of transfer of heat in material bodies, due to the actual movement of the particles of the medium.
b. Convection 2. It is the process of transfer of heat in material bodies, without the actual movement of the particles of the medium.
c. Radiation 3. It is the process of transfer of heat from a hot body to a cold body, without the aid of any external medium.

  1. a - 2, b - 3, c - 1

  2. a - 2, b - 1, c - 3

  3. a - 1, b - 2, c - 3

  4. a - 1, b - 3, c - 2

  5. a - 3, b - 1, c - 2
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This is the correct option. Conduction is the process of transfer of heat in material bodies, without the actual movement of the particles of the medium. Convection is the process of transfer of heat in material bodies, due to the actual movement of the particles of the medium. Radiation is the process of transfer of heat from a hot body to a cold body, without the aid of any external medium.

Multiple choice

Glass when heated cracks because

  1. glass is a bad conductor of heat

  2. it is brittle

  3. on heating it expands unevenly

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Glass is a poor conductor of heat. When heated, the part in contact with the heat source expands, while the rest of the glass remains cool and does not expand, creating internal stress that causes the glass to crack.

Multiple choice

Why is the water in a pond cool even on a hot day?

  1. Surface water goes on evaporating taking heat from the water so water becomes cooler

  2. The surrounding earth of the pond absorbs the heat of the water

  3. Water cannot be heated from surface downward

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Water on the surface of a pond continuously evaporates. Since evaporation is an endothermic process that absorbs heat from the water, it lowers the overall temperature of the pond.

Multiple choice

Radiator is a

  1. Cooling agent

  2. Mixing agent

  3. Separating agent

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A radiator is a heat exchanger used to transfer thermal energy from one medium to another for the purpose of cooling or heating, commonly used in vehicles for cooling.

Multiple choice

Heat from the sun is received by the earth through

  1. conduction

  2. radiation

  3. convection

  4. none of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Since space is a vacuum, heat from the sun cannot travel by conduction or convection; it reaches the earth through electromagnetic waves, which is the process of radiation.

Multiple choice

The mode of propagation of heat from the sun to earth is

  1. conduction

  2. convection alone

  3. radiation alone

  4. convection and radiation
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Since there is a vacuum between the Earth and the Sun, heat cannot travel by conduction or convection, which require a medium. Radiation is the only way heat can travel through a vacuum.

Multiple choice

Which principle is a microwave oven based on?

  1. Heat generation by nuclear power

  2. Heat for microwaves are the same as heat waves

  3. Microwaves vibrate the water molecules in food, thereby generating heat

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Correct Answer: Microwaves vibrate the water molecules in food, thereby generating heat