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 chemistry matter in our surroundings diffusion in different states of matter properties of solids, liquid, and gas particle theory of matter

The more light the object absorbs, the:

  1. less heat absorbed

  2. more heat absorbed

  3. no heat absorbed

  4. maximum heat released
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The more light the object absorbs, the more heat absorbed since light is energy. If you consider it a color, black absorbs the most heat. A black object absorbs all wavelengths of light and reflects none. Objects that are white, on the other hand, reflect all wavelengths of light and therefore absorb the least heat.

Multiple choice chemistry matter in our surroundings diffusion in different states of matter properties of solids, liquid, and gas particle theory of matter

Heat energy is transferred from hot places to cooler places by:

  1. radiation

  2. conduction

  3. convection

  4. all of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Convection occurs when particles with a lot of heat energy in a liquid or gas move and take the place of particles with less heat energy. Heat energy is transferred from hot places to cooler places by convection. Conduction is the transfer of energy through matter from particle to particle. 

Multiple choice chemistry matter in our surroundings diffusion in different states of matter properties of solids, liquid, and gas particle theory of matter

On heating matter, the particles ...... energy and on cooling matter, the particles .......energy.

  1. lose, gain

  2. gain, lose

  3. lose, lose

  4. gain, gain
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

On the heating matter, the kinetic energy of particles increases, so they gain energy and on the cooling matter, the particle's the motion of particles decreases, so they lose energy.

Multiple choice chemistry matter in our surroundings diffusion in different states of matter properties of solids, liquid, and gas particle theory of matter

Steam at ${100^0 C}$ causes more severe burns than the water at the same temperature because:

  1. Steam is a gas

  2. Steam is highly combustible

  3. Steam can provide more heat

  4. Steam cannot do more work
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In addiiton to the temperatre steam has latent heat of vapourization which it acquires after converting into steam from water.

Multiple choice chemistry matter in our surroundings diffusion in different states of matter properties of solids, liquid, and gas particle theory of matter

A solid consists of low kinetic energy, vibrating particles locked into position by interparticle attractive forces. When heat is applied, energy is absorbed and the particles start vibrating more vigorously.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A solid consists of low kinetic energy vibrating particles locked into position by interparticle attractive forces. When heat is applied, energy is absorbed and the particles start vibrating more vigorously.
Finally, the vibrations become energetic enough to overcome the attractive forces, and the particles start sliding out of their positions to flow about. The solid is now melting into a liquid.

Multiple choice chemistry matter in our surroundings diffusion in different states of matter properties of solids, liquid, and gas particle theory of matter

Why does evaporating sweat cools human body?

  1. Condensation

  2. Evaporate cooling

  3. Evaporate heating

  4. Melting
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Evaporation involves conversion of liquid to vapor which happens when latent heat is absorbed by the liquid.

During sweating, human body is cooled by evaporation of sweat molecules which takes place by absorbing latent heat of evaporation from our body.

Multiple choice physics option b: engineering physics conversion of heat into work: heat engine and it's efficiency engines and cycles refrigerators and heat pumps

 What function is performed by Condenser in a refrigerator?

  1. To deliver the heat to the heat pump

  2. To deliver the heat to the evaporator

  3. To deliver the heat to the refrigerator

  4. To deliver the heat to the atmosphere
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A condenser is simply a heat exchanger,the purpose of a condenser in the cycle of compression refrigeration is to change the hot gas being discharged from the compressor to a liquid prepared for use in the evaporator. The condenser accomplishes this action by the removal of sufficient heat from the hot gas, to ensure its condensation at the pressure available in the condenser. The heat is shifted to another medium, like water or air, to cool the condenser.

The function is performed by Condenser in a refrigerator to deliver the heat to the atmosphere

Multiple choice physics option b: engineering physics conversion of heat into work: heat engine and it's efficiency engines and cycles refrigerators and heat pumps

What is the function of refrigerants in heat pumps?

  1. Refrigerants supply heat to the atmosphere

  2. Refrigerants evaporate heat and cool the room

  3. Refrigerant carries heat from the atmosphere to the room,which is to be heated

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

A refrigerant is a substance or mixture, usually a fluid, used in a heat pump and refrigeration cycle. In most cycles it undergoes phase transitions from a liquid to a gas and back again.A heat pump is a device that transfers heat energy from a source of heat to what is called a "heat sink". Heat pumps move thermal energy in the opposite direction of spontaneous heat transfer, by absorbing heat from a cold space and releasing it to a warmer one. A heat pump uses a small amount of external power to accomplish the work of transferring energy from the heat source to the heat sink.


the function of refrigerants in heat pumps refrigerant carries heat from the atmosphere to the room,which is to be heated

Multiple choice physics temperature and heat heat and heat transfer transfer of heat fundamentals of heat transfer

Why do insulators take larger time to heat up?

  1. They need more heat per every degree Celsius rise in temperature.

  2. They need more energy per every degree Celsius rise in temperature.

  3. They need more to perform more work per every degree Celsius rise in temperature.

  4. They need more heat per every degree Farenheit rise in temperature.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Substances which don't allow heat to easily pass through them are known as insulators. Insulators have crystal structure of molecules, molecules are far from each other, compared to conductors. Hence, they cannot pass the heat easily through them, besides this insulators don't have free electrons to pass heat more quickly. Therefore, unit mass of an insulator requires more heat to raise its temperature by $1^{o}$ i.e. specific heat capacity of insulators is very high or we can say they need more heat per degree rise in temperature.

Multiple choice physics temperature and heat heat and heat transfer transfer of heat fundamentals of heat transfer

If needle is burnt then the heat transfer through the whole length of needle is faster because:

  1. needle is a bad conductor of heat

  2. needle is a good conductor of heat

  3. needle is an insulator

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

If needle is burnt then the heat transfer through the whole length of needle is faster, because needle (metal), being a good conductor of heat, heat passes along the whole length by conduction, in which heat is transferred by one atom to another connected atom quickly. 

Multiple choice physics thermal properties heat exchange calorimeter measuring thermal quantities by the method of mixtures

What is the process in which heat energy of both hot and cold body equalizes?

  1. Calorimetry

  2. Fermentation

  3. Latent heat

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

Principle of calorimetry states that heat lost by a hotter body = heat gained by a colder body, therefore calorimetry is a process in which heat energy of both hot and cold body equalizes.