Engineering :: Refrigeration and Air conditioning

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111.

The difference between wet and dry bulb temperature

A.	Increases at atmospheric temperature	B.	Increases as air gets wet
C.	Increases as air gets drier	D.	Remains constant always
E.	None of the above

112.

A low wet bulb temperature indicates

A.	Very cool air	B.	Very low humidity
C.	Very low atmospheric temperature	D.	(A) and (B) above
E.	(A) and (C) above

113.

A cooling tower cools water

A.	Below wet bulb temperature	B.	Equal to wet bulb temperature
C.	Slightly above wet bulb temperature	D.	Wet bulb has no bearing on cooling load performance
E.	None of the above

114.

Capacity of a domestic refrigerator is in the range

A.	0.1 to 0.3 tonnes	B.	1 to 3 tonnes
C.	3 to 5 tonnes	D.	5 to 7 tonnes
E.	7 to 10 tonnes

115.

The coefficient of performance of a domestic refrigerator as compared to that of an air conditioner is gererally

A.	More	B.	Same
C.	Less	D.	Air conditioner performance depends on whether conditions
E.	Cannot be compared

116.

The statement: If a maximum of gases or vapours is enclosed in a container, each will exert its own pressure on the container entirely independent of the others and the total absolute pressure will be equal to the sum of the partial pressure exerted by each of the gases. This statement is known as

A.	Newton's law of gases	B.	Kinetic theory of gases
C.	Fick's law	D.	Avogadro's hypothesis
E.	Dalton's law of partial pressures.

117.

One a psychrometric chart cooling and humidification process using spray can be shown by

A.	A horizontal line	B.	A vertical line
C.	A line parallel to dry bulb temperature lines	D.	A line parallel to wet bulb temperature lines
E.	A curve

118.

Major modification required to produce temperature of - 200?C in a vapour compression refrigeration system using Freon 12 as refrigerant, is

A.	Size of compressor required would be large to handle volumes of vapour	B.	Compression ratio has to be restricted till stronger body of compressor is needed
C.	Condenser capacity must be increased to handle the refrigerant	D.	Insulation should be capable of withstanding such low temperatures
E.	Freon 12 cannot be used for such low temperatures

119.

Super-conductors

A.	Offer no resistance to flow of heat at low temperatures	B.	Offer no resistance to flow of electricity at low remperatures
C.	Cannot be magnetised at low temperatures	D.	Offer no resistance to flow of fluids at low temperatures
E.	Can be rubbed with other superconductors without frictional effects at low temperatures

120.

Ten grams of moisture per kg of dry air is removed from atmospheric air during air conditioning and the temperature becomes 30?C. If the atmospheric conditions are 40?C DBT and 60% Relative humidity, the RH of air after refrigeration would be

A.	60%	B.	50%
C.	40%	D.	69%
E.	104%