Engineering :: Heat Engines

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21.

For initially dry and saturated steam flowing through a nozzle the volue of critical pressure ratio is given by

A.	1	B.	0.528
C.	0.546	D.	0.577
E.	0.75

22.

The equilibrium conditions between supersaurated vapour and a cooled liquid surface are expressed in

A.	Calender's equation	B.	Dalton's equation
C.	Kelvin Helmhotz equation	D.	Napier's equation
E.	Clapcyron's equation

23.

Which is the external loss in a steam turbine?

A.	Nozzle losses	B.	Blade friction losses
C.	Disc friction losses	D.	Gland leakage losses
E.	Back pressure losses

24.

A Lungistrom turbine is

A.	Impulse turbine	B.	Reaction turbine
C.	Outward radial flow turbine	D.	Inward flow impulse reaction turbine
E.	None of the above

25.

The function of a condenser in a steam power plant is

A.	To reduce back pressure	B.	To utilise heat of exhaust steam
C.	To preheat feed water with exhaust steam	D.	To act as a heat sink
E.	To condense feed water

26.

Enthalpy of a substance is defined as

A.	The sum of internal energy and the work done in forcing unit mass of substance into an enclosure at the constant pressure at which the substance exists	B.	Sum of sensible heat + latent heat of substance
C.	Total heat content of substance above zero degree centigrade	D.	Sensible heat of water + work done in forcing unit mass of substance into an enclosure at constant pressure at which the substance exists
E.	None of the above

27.

Presence of impurities in ice

A.	Raises melting point	B.	Lowers melting point
C.	Does not have any effect	D.	Makes it heavier than water
E.	Depends on other factors

28.

Steam consumption per kWh of electricity generated in a modern power plant is of the order of

A.	1 - 2 kgs	B.	2 - 4 kgs
C.	5 - 7 kgs	D.	8 - 10 kgs
E.	10 -12 kgs

29.

Generally steam turbines in power station operate at

A.	3000 RPM	B.	1500 RPM
C.	1000 RPM	D.	375 RPM
E.	50 RPM

30.

The pressure of steam generated in a boiler as recorded by the Bourdon pressure gauge was 2.2 kg/sq-cm. If the barometer reads 774 mm of mercury the absolute pressure of steam would be

A.	0.2 kg/sq-cm	B.	9.774 kg/sq-cm
C.	77.4 mm of Hg	D.	3.2526 kg/sq-cm
E.	1.025 kg/sq-cm