Question

Complete the following:
(a) Heat transfer in solids is by ................., in liquids is by .................. and in gases is by ................. .
(b) Good absorbers are ......................... radiators.
(c) Black (or dull) surfaces are ................ reflectors, but ............... absorbers of heat.
(d) Highly polished surfaces are .............. .
(e) Heat radiations differ from visible light in ............... .

Answer 1

(a) Heat transfer in solids is by conduction , in liquids is by convection and in gases is by convection.

(b) Good absorbers are good radiators (by Kirchhoff's law) .

(c) Black surfaces are poor reflectors , but good absorbers of heat .

(d) Highly polished surfaces are good reflectors , but poor absorbers of heat .(e) Heat radiations differ from visible light in wavelength . (heat radiation is in infrared region) .