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 friction advantages and disadvantages of friction merits and demerits of friction and methods to reduce it friction: a necessary evil

Which of the following is true for friction?

  1. It is necessary to perform many tasks.

  2. It produces heat.

  3. It wears out the surfaces in contact.

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

Friction is important to perform many tasks. It also produces heat in the process and since the two surfaces keep rubbing against each other, they gradually wear out.

Multiple choice viscosity option b: engineering physics properties of matter physics

Why does the cotton wick in an oil filled lamp keep on burning?

  1. By friction

  2. By capillary action

  3. By electrostatic force

  4. By Gravitational force
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Due to surface tension of oil capillary rise can be seen in cotton wick which makes lamp to burn.

Multiple choice physics heat engine: second law of thermodynamics second law of thermodynamics the second law of thermodynamics second law of thermodynamic

Heat flows between two bodies due to difference in their temperature.

  1. True

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

Heat is defined as the energy which passes between two objects because of the difference in temperature. Thus energy may pass between them, but not heat. It is possible that the energy absorbed may increase the temperature, particularly if work is done, but this is not heat transfer.


Heat flows between two bodies due to difference in their temperature.

Option A is true

Multiple choice physics heat engine: second law of thermodynamics second law of thermodynamics the second law of thermodynamics second law of thermodynamic

The statement "It is impossible  to construct a heat engine which can convert heat directly to work completely" was given by

  1. Clausius

  2. Carnot

  3. Plank

  4. Kelvin & Plank
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The second law of thermodynamics states , that it is impossible to construct a heat engine , operating in cycle , which extracts heat and can convert it all to useful work .In other words , it is impossible for a heat engine to convert heat completely in work .This statement is given by Kelvin & Plank .

Multiple choice physics heat engine: second law of thermodynamics second law of thermodynamics the second law of thermodynamics second law of thermodynamic

Choose the correct options for the following statements :

A) First law of thermodynamics specifies the conditions under which a body can use its heat energy to produce the work.
B) Second law of thermodynamics states that heat always flows from hot body to cold body by itself.

  1. Both A and B are true

  2. Both A and B are false

  3. A is true but B is false

  4. A is false B is true
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

First law of thermodynamics just states that $dQ = dW + dU $. 


It does $not$ tell us whether the process is feasible or not neither does it provide any condition to under which the body uses any energy.
Hence, A is false.

Second law of thermodynamics states that heat always flows from hot body to cold body by itself and for heat to flow from a cold body to hot body, external work should be done. 
Thus, B is true.

Multiple choice physics properties of waves longitudinal and transverse waves travelling waves types of waves

Which of the following can travel through vacuum?

  1. Light waves

  2. Heat waves
  3. $X$-rays

  4. Sound waves
Reveal answer Fill a bubble to check yourself
A,B,C Correct answer
Explanation

Heat rays are infra-red rays.

Light rays, infra-red rays and X-rays are all electromagnetic rays.
Electromagnetic rays can travel through vacuum and through transperent media.
However, sound waves are mechanical longitudinal waves. They need a material medium for travelling. They can't travel through vacuum.

Multiple choice physics temperature and heat applications of heat conduction applications of insulation clothes - our necessity

Air is a good conductor of heat. True or false.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
False
Air is bad conductor of heat. It is due to the air trapped between the cotton molecules which gives warmth on taking quilt in winter It is due to air molecules trapped between wool fabrics which provide warmth to body during winter season.
Multiple choice physics temperature and heat applications of heat conduction applications of insulation clothes - our necessity
Metal floors cool more than a wood floor in winters because:

  1. Metal conducts heat more readily than wood

  2. Wood conducts heat more readily than metal

  3. Metal has a higher specific heat than wood

  4. The temperature of the wood is higher than the temperature of the metal

  5. The temperature of the metal is higher than the temperature of the wood
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Metals are good conductor of heat whereas wood does not conduct heat at all.

Thus in winters, metal floors cool more than a wood floor.

Multiple choice physics transfer of heat applications of heat conduction applications of insulation clothes - our necessity

State the correct statement

  1. When we heat an object, it becomes hot

  2. When we heat an object, it expands in size

  3. When we heat an object, it changes its such such as water boils to form water vapour

  4. All of them are true
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

When we heat an object, it changes its shape, nature and it becomes hot, the temperature increases due to movement of atoms.

Multiple choice physics transfer of heat applications of heat conduction applications of insulation clothes - our necessity

The ............ the conductor, the more rapidly does heat transfer takes place.

  1. better

  2. worse

  3. thinner

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

The better the conductor, the more rapidly does heat transfer takes place .


Better conductor means more thermal conductivity; more the thermal conductivity; more rapidly the heat transfer takes place.

Multiple choice physics transfer of heat applications of heat conduction applications of insulation clothes - our necessity

The heat capacity of a body depends on 

  1. the heat given

  2. the temperature rasied

  3. the mass of the body

  4. the material of he body.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Heat capacity (C) is defined as the amount of heat required to raise the temperature of a body by one degree. It is given by C = m * c, where m is the mass and c is the specific heat capacity of the material.