Physics · Science General

Heat Transfer Mechanisms

828 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 bio-chemistry caskets of life animal cells vs plant cells comparing plant and animal cells comparison between animal and plant cell

The interior of a cow-dung pile kept for a few days is quite warm. This is mostly because: 

  1. Cellulose present in the dung is a good insulator.

  2. Bacterial metabolism inside the dung releases heat.

  3. Undigested material releases heat due to oxidation by air.

  4. Dung is dark and absorbs a lot of heat.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

At the later stages of decomposition of cowdung, mesophilic micro-organisms decompose the dung, generating heat from exothermic( process which produces heat) processes; such heat generation is associated with the well known phenomenon of the elevated temperature of composting.

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 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.

Multiple choice physics heat - measurement introduction to temperature application of various thermometric scales different types of thermometers

Heat causes-

  1. change in temperature

  2. chemical change

  3. biological change

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

heat is a type of energy transfer in which energy flows from a warmer substance or object to a colder one. It can be defined as the total amount of transferred energy excluding any macroscopic work that was done and any transfer of part of the object itself. Transfer of energy as heat can occur through direct contact, through a barrier that is impermeable to matter (as in conduction), by radiation between separated bodies, by way of an intermediate fluid (as in convective circulation), or by a combination of these. By contrast to work, heat involves the stochastic (random) motion of particles (such as atoms or molecules) that is equally distributed among all degrees of freedom, while work is confined to one or more specific degrees of freedom such as those of the center of mass.

Heat causes change in temperature,chemical change,biological change.

Multiple choice physics heat - measurement introduction to temperature application of various thermometric scales different types of thermometers

Heat of conduction flows in the direction of decreasing: 

  1. Temperature

  2. Pressure

  3. Density

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Heat of conduction flows in the direction of decreasing Temperature
The objects will exchange thermal energy, until thermal equilibrium is reached, i.e. until their temperatures are equal.  We say that heat flows from the hotter to the cooler object.  Heat is energy on the move.  
Units of heat are units of energy.  The SI unit of energy is Joule.  Other often encountered units of energy are 1 Cal = 1 kcal = 4186 J, 1 cal = 4.186 J, 1 Btu = 1054 J.
Multiple choice physics heat - measurement introduction to temperature application of various thermometric scales different types of thermometers

Heat flow can occur due to which of the following situation

  1. Pressure difference

  2. Temperature difference

  3. Density difference

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

Heat can be transferred from one place to another by three methods: conduction in solids, convection of fluids (liquids or gases), and radiation through anything that will allow radiation to pass. The method used to transfer heat is usually the one that is the most efficient. If there is a temperature difference in a system, heat will always move from higher to lower temperatures.

So, Heat flow occurs due to Temperature Difference