- Heat Transfer
- Heat Conduction
- Thermal Conductivity
- Thermal resistance and conductance
- Convection heat transfer
- Black Body Radiation
- Stefan Boltzmann law
- Nature of thermal Radiation
- Kirchoff's law
- Newton's Law of Cooling
- Solved examples

**Multiple choice questions with one or more answers**

**Question 1.** A Cylinder of radius R made of a material having thermal conductivity K is surrounded by a parrallopied having inner hole of radius R and outer dimension of 3 R each. Thermal conductivity of parrallopied is 2K

The effective thermal conductivity of the system

a, K[2 + (π/9)]

b, K[2 + (π)]

c, K[2 - (π/9)]

d, 3 K

Solution

λ

which of the these is true for the temperatures

a, T

b, T

c, T

d, T

Solution

All Rod are of equal length and equal area of cross-section. Find the temperature at point B

a, 45

b, 51.4

c, 50

d, 51

Solution

Three identical rods are connected between two container contained at Temp. T

Let Q

when of these is true.

a, Q

b, Thermal resistance is maximum in fig(a)

c, Q

d, All the above

Solution

A rod of thermal conductivity K and area A and length L is there. The initial temperature distribution along the rod is given by

T = T

where T

a.

b.

c.

d.

Solution

a, T

b, T

c, T

d, T

Solution

a, πKAT

b, KAT

c, 3KAT

d, 4KAT

Solution

a, zero

b, KAT

c, 2KAT

d, 2KAT

Solution

a.

b.

c.

d.

a.(a = 1) , (e = 1)

b, Reflect radiation & refract radiation

c, frequency of radiation which is dominant is directly proportional to the temperature of the body

d, All of the above

There are two bodies A & B they are having same surface and same mass. They are at temperature T at time t=0

Temperature of the surrounding is T

Given (T > T

Let a

which of these is true

a, Body A will cool faster than body B

b, Emissivity is greater for body B

c, Emissivity is greater for body A

d, Body B will cool faster than body A

Solution

Two sphere A & B are there of same material

sphere A is hollow sphere

sphere B is solid sphere

Radius is same for both the sphere

They are at same temperature T

Two statement are made about the above scenario

A) dT/dt at t = 0 will be same for the sphere

(B) Emissive power of both the sphere will be same in the beginning

(a) A & B both are correct

(b) Only B is correct

(c) Only A is correct

(d) None of them is correct

Solution

a. A will cool faster for all values of T

b. A & B both will cool at same rate for all values of T

c. A & B will have equal temperature at any instant

d none of the above

Solution

a E

b.E

c. E

d. E

Solution

A hot body whose temperature is T is kept in a room where temperature is T

Also T > T

and T - T

which one of the following is true

a. t

a. t

a. t

d. None of the above

Solution

a.

b.

c.

d.

a E

b.E

c. E

d. E

temperature

a E

b.E

c. E

d. E

Solution

Solution

A composite slab is prepared by pasting three slab of thickness L

a.K

b.K

c. K

d. L

Class 11 Maths Class 11 Physics Class 11 Chemistry