Heat Transfer (3151909) MCQs

MCQs of Conduction

Showing 11 to 20 out of 36 Questions
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11.

when heat is transferred from one particle of hot body to another by actual motion of the heated particles, it is referred to as heat transfer by

(a)

conduction
(b)

convection
(c)

radiation
(d)

none of the above
Answer:

Option (a)

12.

Thermal diffusivity of a substance is

(a)

directly proportional to thermal conductivity
(b)

inversely proportional to density of substance
(c)

inversely proportional to specific heat
(d)

all of the above
Answer:

Option (d)

13.

Pick up the wrong case. Heat flowing from one side to other depends directly on

(a)

Face area
(b)

Time
(c)

Thickness
(d)

Temperature difference
Answer:

Option (c)

14.

Which of the following would lead to a reduction in thermal resistance?

(a)

In conduction, reduction in the thickness of the material, and an increase in thermal conductivity.
(b)

In convection, stirring of the fluid and cleaning the heating surface.
(c)

In radiation, increasing the temperature and reducing the emissivity.
(d)

All of the above
Answer:

Option (d)

15.

Thermal conductivity of air with rise in temperature

(a)

Increases
(b)

Decreases
(c)

Remain constant
(d)

May increase or decrease depending on temperature
Answer:

Option (a)

16.

The concept of overall coefficient of heat transfer is used in heat transfer problems of

(a)

Conduction
(b)

Convection
(c)

Radiation
(d)

Conduction and Convection
Answer:

Option (d)

17.

The amount of heat flow through a body by conduction is

(a)

Directly proportional to the surface area of the body
(b)

Directly proportional to the temperature difference on the two faces of the body
(c)

Dependent upon the material of the body
(d)

All of the above
Answer:

Option (d)

18.

Unit of the rate of heat transfer is

(a)

Joule
(b)

Newton
(c)

Pascal
(d)

Watt
Answer:

Option (d)

19.

Heat transfer in a long, hollow cylinder which is maintained at uniform but different temperatures on its inner and outer surfaces may be assumed to be taking place in which direction?

(a)

Axial only
(b)

Unpredictable
(c)

Radial only
(d)

No heat transfer takes place
Answer:

Option (c)

20.

Mark the matter with least value of thermal conductivity

(a)

Air
(b)

Water
(c)

Ash
(d)

Window glass
Answer:

Option (a)

Showing 11 to 20 out of 36 Questions
1 2 3 4