Engineering :: Heat Transfer

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101.

Pyrometer which react to all wavelengths of incident radiant energy are known as

A.	Optical pyrometers	B.	Ddisappearing filament type pyrometers
C.	Polarising pyrometers	D.	Total radiation pyrometers
E.	Multicolour pyrometers

102.

The statement that the emissivity and absorptivity of a surface is surrounded by its own temperature are the same for both monochromatic and total radiation, is known as

A.	Stefan Boltzman low	B.	Kirchhoff's law
C.	D'Alembert's rule	D.	Lambert law
E.	Law of emissivity

103.

The rate of radiant energy, which is emitted by a surface at any temperature and in small wavelength is found from the known rate of energy, which under the same condition would be emitted from a black surface by multiplying with the absorptivity. Above enunciation is known as

A.	Planck's law	B.	Kirchhoff's law
C.	Stefan Boltzman law	D.	Lambert rule
E.	None of the above

104.

Elongation of a rod when heated

A.	Is proportional to length	B.	Is proportional to original length
C.	Is inversely proportional to original length	D.	Is inversely proportional to linear strain
E.	Does not depend on its length

105.

When a vapour condenses into a liquid

A.	It absorbs heat	B.	It evolves heat
C.	Its temperature rises	D.	Its temperature drops
E.	None of the above

106.

A vapour containing liquid particles to the extent of 50% by the volume is known as

A.	Saturated liquid	B.	Super saturated liwuid
C.	Wet vapour	D.	Saturate vapour
E.	Superheated vapour

107.

Unsaturated vapours

A.	Do not obey gas laws	B.	Fully obey gas laws
C.	Obey Boyle's law and not Boyles law	D.	Partly obey gas laws depending upon the degree of unsaturation

108.

Ice is slippery when a man walks on it for

A.	Its surface is smooth	B.	There is no friction
C.	It is very chill	D.	Increase of pressure causes it to melt
E.	It has lubricating qualities

109.

Formation of fog is due to

A.	Low pressure	B.	High pressure
C.	Night showers	D.	Humidity
E.	Temperature fall of atmosphere

110.

Hygrometer is used to measure

A.	Convective heat transfer coefficient	B.	Heat exchanged due to vapour
C.	Density of liquids	D.	Relative humidity
E.	None of the above