Explore topic-wise MCQs in Steam Nozzles and Turbines.

This section includes 27 Mcqs, each offering curated multiple-choice questions to sharpen your Steam Nozzles and Turbines knowledge and support exam preparation. Choose a topic below to get started.

1.

The difference of supersaturated temperature and saturation temperature at that pressure is known as .......

A. Degree of supersaturation
B. Degree of superheat
C. Degree of undercooling
D. None of these
Answer» D. None of these
2.

For a convergent divergent nozzle,critical pressure ratio occurs when ......

A. Velocity at exit becomes sonic
B. Shock wave of occurs
C. Nozzle efficiency is maximum
D. Increase in exit and inlet pressure ratio does not increase steam flow rate
Answer» E.
3.

The superposition of steam results in slight......

A. Increase in entropy
B. Increase of final dryness fraction
C. Increase of discharge
D. All the above
Answer» E.
4.

For critical pressure ratio, the discharge through a nozzle is.......

A. Maximum
B. Minimum
C. Zero
D. Some value between maximum and minimum
Answer» B. Minimum
5.

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» E.
6.

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» D. Increase the enthalpy drop
7.

The critical pressure ratio for initially superheated steam is.......as compared to initially dry saturated steam

A. More
B. Less
C. Same
D. None of the above
Answer» C. Same
8.

A nozzle is said to be choked when .......

A. Flow-through it is zero
B. Flow is attained at maximum value corresponding to critical exit pressure
C. It is not possible to increase the flow by increasing inlet pressure
D. It is discharging into atmosphere
Answer» C. It is not possible to increase the flow by increasing inlet pressure
9.

The Effect of friction in a nozzle......dryness fraction of steam

A. Increases
B. Decreases
C. Same
D. None of the above
Answer» B. Decreases
10.

If a flow is to be continuously accelerated from a subsonic to a supersonic velocity in nozzle,it must ......

A. Be convergent
B. Be divergent
C. Have throat
D. Have first divergent section and then convergent section
Answer» D. Have first divergent section and then convergent section
11.

For a convergent divergent nozzle, the mass flow rate remains constant if the ratio of exit and inlet pressures.........

A. Is less then critical pressure ratio
B. Is equal to the critical pressure ratio
C. Is more then critical pressure ratio
D. Is infinity
Answer» D. Is infinity
12.

Mack number is more than unity in the following portion of a convergent divergent nozzle......

A. Convergent potion
B. Straight portion
C. Throat
D. Divergent potion
Answer» E.
13.

Under thermal equilibrium, flow of steam is.......

A. Isentropic
B. Adiabatic
C. Hyperbolic
D. Polytropic
Answer» C. Hyperbolic
14.

The effect of friction in 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» C. Decrease dryness fraction
15.

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

A. Steam engine
B.
C. C.
D. D.
Answer» C. C.
16.

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» D. Slightly more than sonic velocity
17.

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» E.
18.

The value of critical pressure ratio for initially wet steam is.......

A. 0.546
B. 0.5
C. 0.554
D. 0.582
Answer» E.
19.

The value of critical pressure ratio for superheated steam is.......

A. 0.5
B. 0.546
C. 0.454
D. 0.64
Answer» C. 0.454
20.

The flow of steam in a nozzle is subsonic at......

A. Throat
B. Entrance
C. Convergent portion
D. Divergent portion
Answer» D. Divergent portion
21.

In convergent nozzle velocity velocity attained is.......

A. Velocity of sound
B. Supersonic velocity
C. Around 500 m/sec
D. 1000 meter/sec
Answer» E.
22.

The steam leaves the nozzle at a.........

A. High pressure and low velocity
B. High-pressure and high velocity
C. Low pressure and low velocity
D. Low pressure and high velocity
Answer» E.
23.

Shock effect in a nozzle is felt in.........

A. Divergent portion
B. Straight portion
C. Convergent portion
D. Throat
Answer» B. Straight portion
24.

Nozzle efficiency is described as.......

A. Isentropic heat drop/useful heat drop
B. useful heat drop/isentropic heat drop
C. saturation temperature/supersaturation temperature
D. supersaturation temperature/saturation temperature
Answer» C. saturation temperature/supersaturation temperature
25.

The critical pressure ratio for initially dry saturated steam is.......

A. 0.528
B. 0.546
C. 0.577
D. 0.582
Answer» D. 0.582
26.

The impulse turbine rotor efficiency will have a maximum value of 0.5 cos2 , where is the nozzle exit flow angle, if the

A. blades are equiangular
B. blade velocity coefficient is unity
C. blades are equiangular and frictionless
D. blade solidity is 0.65
Answer» D. blade solidity is 0.65
27.

The efficiency of a pressure-velocity compounded impulse turbine is __________ as compared to pressure compounded impulse turbine

A. same
B. less
C. more
Answer» C. more