73) The thermal diffusivities for solids are generally

Answer is:

more than those for liquids and gases

Heat transfer MCQ with Answers

74) Thermal diffusivity of a substance is

Answer is:

all of the above

Explanation:

Thermal diffusivity of a substance is
* directly proportional to the thermal conductivity
* inversely proportional to density of substance
* inversely proportional to specific heat

75) The ratio of the emissive power and absorptive power of all bodies is the same and is equal to the emissive power of a perfectly black body. This statement is known as

Answer is:

Krichoff′s law

76) According to Stefan′s law, the total radiation from a black body per second per unit area is proportional to

Answer is:

t

77) According to Wien′s law, the wavelength corresponding to maximum energy is proportion to

Answer is:

absolute temperature (T)

Heat transfer MCQ with Answers

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73) The thermal diffusivities for solids are generally

more than those for liquids and gases

Heat transfer MCQ with Answers

Related Heat transfer MCQ with Answers

74) Thermal diffusivity of a substance is

all of the above

75) The ratio of the emissive power and absorptive power of all bodies is the same and is equal to the emissive power of a perfectly black body. This statement is known as

Krichoff′s law

76) According to Stefan′s law, the total radiation from a black body per second per unit area is proportional to

t

77) According to Wien′s law, the wavelength corresponding to maximum energy is proportion to

absolute temperature (T)

Heat transfer MCQ with Answers