Power Plant Engineering (2171910) MCQs

MCQs of Steam Nozzles

Showing 21 to 30 out of 41 Questions
1 2 3 4 5
21.

The flow of steam is supersonic

(a)

at the entrance to the nozzle 
(b)

at the throat of the nozzle
(c)

in the convergent portion of the nozzle
(d)

in the divergent portion of the nozzle
Answer:

Option (d)

22.

The maximum velocity attainable at the throat of a steam nozzle is

(a)

much less than sonic velocity 
(b)

slightly less then sonic velocity 
(c)

sonic velocity
(d)

slightly more than sonic velocity
Answer:

Option (c)

23.

Which of the following devices uses wilson's line in determining flow through it?

(a)

Steam engine 
(b)

Steam nozzle
(c)

Reaction turbine 
(d)

Impulse turbine
Answer:

Option (b)

24.

The effect of friction in the nozzle is to 

(a)

keep dryness fraction constant 
(b)

increase dryness fraction 
(c)

decrease dryness fraction 
(d)

first increase dryness fraction upto certain limit and then decrees it 
Answer:

Option (b)

25.

The flow through a nozzle is regarded as

(a)

constant volume flow
(b)

constant pressure flow
(c)

isothermal flow
(d)

isentropic flow
Answer:

Option (d)

26.

The shock effect in a nozzle is felt in

(a)

divergent portion 
(b)

straight portion
(c)

convergent portion
(d)

throat
Answer:

Option (a)

27.

In a nozzle, the effect of supersaturation is to

(a)

decrease the dryness fraction of steam
(b)

decreases the specific volume of steam 
(c)

increase the entropy 
(d)

increase the enthalpy drop
Answer:

Option (c)

28.

That density of super saturated steam is about.........that of the ordinary saturated vapour at the corresponding pressure

(a)

same as
(b)

2 times
(c)

4 times
(d)

8 times
Answer:

Option (d)

29.

For critical pressure ratio, the discharge through a nozzle is

(a)

maximum
(b)

minimum
(c)

zero
(d)

some value between maximum and minimum
Answer:

Option (a)

30.

The critical pressure gives the velocity of steam at the throat

(a)

equal to the velocity of sound
(b)

less than the velocity of sound
(c)

more than the velocity of sound
(d)

none of these
Answer:

Option (a)

Showing 21 to 30 out of 41 Questions
1 2 3 4 5