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 physics temperature and heat modes of heat transfer - conduction conduction heat and modes of heat transfer

At a common temperature ,a block of wood and a block of metal feel equally cool or hot. The temperatures of metal and wood are

  1. $Less$ $than$ $the$ $temperature$ $of$ $the$ $body$
  2. $Equal$ $than$ $the$ $temperature$ $of$ $the$ $body$
  3. $Greater$ $than$ $the$ $temperature$ $of$ $the$ $body$
  4. $Either$ $(a)$ $or$ $(c)$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When objects are at the same temperature as the surroundings, they feel different because of their thermal conductivity. Metal conducts heat away from the hand faster than wood, making it feel colder, even though they are at the same temperature.

Multiple choice physics temperature and heat modes of heat transfer - conduction conduction heat and modes of heat transfer

Choose the correct experiment to demonstrate the transfer of heat by the process of conduction.

  1. Take two metal blocks of same size & shape and heat one of them to a considerable temperature, then allow both the blocks to touch each other, after a while, you will see the other block gets heated due to contact.

  2. Take two metal blocks of same size & shape and heat one of them to a considerable temperature, then keep the blocks separate, after a while you will see the other block gets heated due to contact.

  3. Take two metal blocks of same size & shape and heat one of them to a considerable temperature, then allow both the blocks to touch each other after the block get cooled down, after a while you will see the other block gets heated due to contact.

  4. None of above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Take two metal blocks of same size & shape and heat one of them to a considerable temperature, then allow both the blocks to touch each other, after a while you will see the other block gets heated due to contact.

Multiple choice physics temperature and heat modes of heat transfer - conduction conduction heat and modes of heat transfer

State true or false:
The more is the temperature difference of hot and cold body more slowly the heat flows from it into the cold body

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
The amount of heat leaving the hot object will be equal to the amount of heat received by the colder object (assuming nothing else is around to receive some of the heat). The rate at which heat transfers from the hotter object to the colder object increases with the temperature difference between the objects.
Multiple choice physics temperature and heat modes of heat transfer - conduction conduction heat and modes of heat transfer

By which of the following methods could a cup of hot tea lose heat when placed on metallic table in a class room
a) conduction
b) convection
c) radiation
d) evaporation of liquid.

  1. a, b

  2. b,c

  3. a,b,c

  4. a,b,c,d
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Conduction occurs through the walls of the cup.
Radiation occurs from the top surface.
Convection occurs at the top of the cup.
Evaporation of liquid also occurs.

Multiple choice physics temperature and heat modes of heat transfer - conduction conduction heat and modes of heat transfer

A red hot brick is placed on an iron tripod stand which stands on a large block of copper. The brick loses heat by:

  1. conduction

  2. conduction and radiation

  3. conduction and convection

  4. conduction, convection, and radiation
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The brick loses heat (i) by conduction through iron tripod stand to the copper block which is then radiated away and convection currents are set up in the surrounding air, and (ii) by radiation.

Multiple choice physics temperature and heat modes of heat transfer - conduction conduction heat and modes of heat transfer

A long silver tea spoon is placed in a cup filled with hot tea. After some time, the exposed end (the end which is not dipped in tea) of the spoon becomes hot even without a direct contact with the tea. This phenomenon can be explained mainly by_______

  1. conduction

  2. reflection

  3. radiation

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

As atoms in the spoon vibrates about their equilibrium positions and transfer energy form one end to other end. This process is called conduction.

Multiple choice physics temperature and heat modes of heat transfer - conduction conduction heat and modes of heat transfer

Which of the following minimizes the transference of heat in a thermos flask?
$1$. Conduction
$2$. Convection
$3$. Radiation

  1. $2$ and $3$
  2. $1$ and $2$
  3. $1, 2$ and $3$
  4. $1$ and $3$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A thermos flask uses a vacuum (to stop conduction and convection) and silvered surfaces (to stop radiation) to minimize all three modes of heat transfer.

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

Which of the following is a type of latent heat?

  1. Latent heat of fusion

  2. Latent heat of vaporization

  3. Both a and b

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

The latent heat is used in change of states of matter, such as from solid to liquid or from liquid to gas without rising in temperature. When solid changes into liquid, the heat required for changing the state without rise in temperature is called the Latent Heat of Fusion. When liquid changes into gas because of rise in temperature, the heat required changing the state without rising in temperature is called the Latent Heat of vaporization.

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

................... reflects all heat, .................... absorbs all heat.

  1. White, black

  2. Black, white

  3. White, yellow

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

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

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.

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

Which produces more burn, steam or boiling water?

  1. Steam

  2. Boiling water

  3. Both produces same burn

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

Water vapour at 373K has more energy than water at 373K as the steam has absorbed latent heat of vaporisation to change the state. Therefore the more burning sensation.

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

The process that absorbs latent heat is:

  1. melting

  2. evaporating

  3. sublimation

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

Latent heat is energy released or absorbed, by a body or a thermodynamic system, during a constant-temperature process that is specified in some way. An example is latent heat of fusion for a phase change, melting, at a specified temperature and pressure. Latent heat is associated with the phase changes of atmospheric water vapor, mostly vaporization and sublimation.