Power Plant Engineering (2171910) MCQs

MCQs of Steam Turbine

Showing 41 to 50 out of 61 Questions
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41.

The pressure compounded impulse turbine as compared to velocity compounded turbine require __________ number of stages.

(a)

same
(b)

less
(c)

more
(d)

can't predict
Answer:

Option (c)

42.

In a reaction turbine

(a)

the steam is allowed to expand in the nozzle, where it gives a high velocity before it enters the moving blades
(b)

the expansion of steam takes place partly in the fixed blades and partly in the moving blades
(c)

the steam is expanded from a high pressure to a condenser pressure in one or more nozzles
(d)

the pressure and temperature of steam remains constant
Answer:

Option (b)

43.

A stage in reaction turbine is represented by

(a)

number of casing
(b)

number of entries of steam
(c)

number of exits of steam
(d)

each row of blades
Answer:

Option (d)

44.

The Parsons' reaction turbine has

(a)

only moving blades
(b)

only fixed blades
(c)

identical fixed and moving blades
(d)

fixed and moving blades of different shape
Answer:

Option (c)

45.

For a Parson's reaction turbine, if α1 and α2 are fixed blade angles at inlet and exit respectively and β1 and β2 are the moving blade angles at the entrance and exit respectively, then

(a)

α1 = α2 and β1 = β2
(b)

α1 = β1 and α2 = β2
(c)

α1 < β1 and α2 > β2
(d)

α1 = β2 and β1 = α2
Answer:

Option (d)

46.

The degree of reaction is given by

(a)

Heat drop in moving blades / total heat drop in the stage
(b)

Heat drop in fixed blades / total heat drop in the stage
(c)

Heat drop in moving blades / Heat drop in fixed blades
(d)

total heat drop in the stage / Heat drop in fixed blades
Answer:

Option (a)

47.

In a reaction turbine when the degree of reaction is zero, then there is

(a)

no heat drop in moving blades
(b)

no heat drop in fixed blades
(c)

maximum heat drop in moving blades
(d)

maximum heat drop in fixed blades
Answer:

Option (a)

48.

The isentropic enthalpy drop in moving blade is two-third of the isentropic enthalpy drop in fixed blades of a turbine. The degree of reaction will be

(a)

0.4
(b)

0.56
(c)

0.67
(d)

1.67
Answer:

Option (a)

49.

The ratio of the workdone on the blades to the energy supplied to the blades, is called

(a)

blading efficiency
(b)

nozzle efficiency
(c)

gross or stage efficiency
(d)

mechanical efficiency
Answer:

Option (a)

50.

The diagram efficiency is the ratio of

(a)

work done on the blades to the energy supplied to the blades
(b)

workdone on the blades per kg of steam to the total energy supplied per stage per kg of steam
(c)

energy supplied to the blades per kg of steam to the total energy supplied per stage per kg of steam
(d)

none of the mentioned
Answer:

Option (a)

Showing 41 to 50 out of 61 Questions
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