Tag: heat and modes of heat transfer

Quizzes (0) Questions (82)

Questions Related to heat and modes of heat transfer

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

The thermal conductivity of the plate depends upon

  1. the temperature difference between the two sides

  2. the thickness of the plate

  3. the area of the plate

  4. nature of the material
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Thermal conductivity of any object depends solely on the material of the object.
It is an intrinsic property and is independent on dimensions/mass/etc of the body.
For example, all iron rods will have same thermal conductivity.
All copper rods will have same thermal conductivity.
But, thermal conductivity of iron rod will be different from that of copper rod.

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

Which of the following qualities are best suited for handling a cooking utensil?

  1. high specific heat and low thermal conductivity

  2. high specific heat and high thermal conductivity

  3. low specific heat and low thermal conductivity

  4. low specific heat and high thermal conductivity
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

High specific heat means high energy required to increase temperature.
Hence for a given amount of energy, temperature would be less for high specific heat.
Low conductivity means heat is not conveyed to all portions of the conductor easily.
Hence, handling the instrument would be easy.

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

Conduction is:

  1. the process of transfer of heat which does not require any material medium

  2. the process of transferring heat from molecule to molecule, without the actual movement of molecules

  3. the process in which molecules conduct heat by moving from hotter regions to colder regions

  4. the process in which heat energy moves through the medium of protons
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Conduction is defined as the process of transferring heat from molecule to molecule, without the actual movement of molecules.

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

The coefficient of thermal conductivity of a metallic rod does not depend upon :

  1. the length of the rod

  2. the cross-sectional area of the rod

  3. the temperature difference between the ends of the rod

  4. the nature of the metal
Reveal answer Fill a bubble to check yourself
A,B,C Correct answer
Explanation

Coefficient of $Thermal$ $Conductivity$ is the internal property of the metal and is independent of all the $external$ properties of the material.

So Coefficient of $Thermal$ $Conductivity$ is independent of dimensions, temperatures and other external factors too. It only depend on nature of material.

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

Conduction is ,

  1. the process of transfer of heat which does not require any material medium

  2. the process of transferring heat from molecule to molecule, with out any movement of molecules

  3. the process in which molecules conduct heat by moving from hotter regions to colder regions

  4. the process in which heat energy moves through the medium of protons
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Conduction is the process by which heat or electricity is directly transmitted through the material of a substance without movement of the material.

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

It is warmer to have two thin blankets than to have single thick blanket because:

  1. Thick blankets cannot give more warmth

  2. Two blankets allow more heat to pass through them

  3. Air between the two blankets is a good conductor of heat

  4. Air between the thin blankets does not allow heat to pass through it since it is a bad conductor
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Air is bad conductor of heat, so it does not allow the heat to pass through, while the single thick blanket is a better conductor of heat so it is less effective.

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

In which mode of transfer of heat molecules pass on heat energy to neighbouring molecules without actually moving from their positions?

  1. convection

  2. radiation

  3. conduction

  4. none of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Conduction is the mode of heat transfer of heat molecules pass on heat energy to neighbouring molecules without actually moving from their positions.
Conduction is the transfer of heat from one substance to another by direct contact without mixing of masses.
Multiple choice physics temperature and heat modes of heat transfer - conduction conduction heat and modes of heat transfer

In a steady state the temperature of the ends A and B of a 20 cm long rod AB is 100$^o$C and 0$^o$C. The temperature at the point c distant 9 cm from a is :

  1. $45^o$C

  2. $55^o$C

  3. $60^o$C

  4. $65^o$C
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Temperature increasing per unit length $=\cfrac{100-0}{20}=5^oC/cm$
Temperature at $9cm$ from $a \\ =100^oC-(5^oC/cm\times 9cm) \\ =55^oC$