MCQs of Radiation (Heat Transfer - 3151909)

Showing 11 to 20 out of 27 Questions

11.

A body that reflects all the incident thermal radiations is called a

12.

Radiation heat transfer is characterized by

(a)	Due to bulk fluid motion, there is a transport of energy
(b)	Thermal energy transfer as vibrational energy in the lattice structure of the material
(c)	Movement of discrete packets of energy as electromagnetic waves
(d)	There is circulation of fluid by buoyancy effects

13.

The absorptivity of the black body equals to

14.

The reciprocity theorem states that

15.

The interchange factor for body 1 completely enclosed by body 2 (body 1 is large) is given by

16.

A radiation shield should

(a)	Have high transmissivity
(b)	Absorb all the radiations
(c)	Have high reflexive power
(d)	Partly absorb and partly transmit the incident radiation

17.

A radiation shield is used between the emitting surfaces such that

(a)	To reduce overall heat transfer
(b)	To increase overall heat transfer
(c)	To increase density
(d)	To reduce density

18.

Which of the following can be used as a radiating shield?

19.

A perfectly black body

(a)	absorbs all the incident radiation
(b)	allows all the incident radiation to pass through it
(c)	reflects all the incident radiation
(d)	has its surface coated with lamp black or graphite

20.

A body which partly absorbs and partly reflects but does not allow any radiation to pass through it $α + ρ = 1 a n d τ = 0$

Showing 11 to 20 out of 27 Questions