Steam Turbine - Mechanical Engineering (MCQ) questions and answers

1)   The blade speed ratio of impulse turbine is given as ___________

a. (Blade velocity) / (Steam velocity at inlet)
b. (Blade velocity) / (Steam velocity at exit)
c. (Steam velocity at inlet) / (Blade velocity)
d. (Steam velocity at exit) / (Blade velocity)
Answer  Explanation 

ANSWER: (Blade velocity) / (Steam velocity at inlet)

Explanation:
No explanation is available for this question!
2)   Which of the following are effects of nozzle friction?

1. Enthalpy drop decreases
2. Exit velocity reduces
3. Decrease in specific volume
4. Decrease in mass flow rate

a. (1), (2) and (3)
b. (2), (3) and (4)
c. (1), (3) and (4)
d. (1), (2) and (4)
Answer  Explanation 

ANSWER: (1), (2) and (4)

Explanation:
No explanation is available for this question!
3)   The passage of uniformly varying cross-section in which the kinetic energy of steam increases at the expense of its pressure is called as__________

a. steam turbine
b. steam nozzle
c. steam area
d. all of the above
Answer  Explanation 

ANSWER: steam nozzle

Explanation:
No explanation is available for this question!
4)   How does the change in velocity of the steam in steam nozzle take place? Select the correct graph in the diagram below.

a. (1)
b. (2)
c. (3)
d. (4)
Answer  Explanation 

ANSWER: (3)

Explanation:
No explanation is available for this question!
5)   The nozzle efficiency can be defined as the ratio of

a. isentropic enthalpy drop to actual enthalpy drop
b. actual enthalpy drop to isentropic enthalpy drop
c. isothermal enthalpy drop to isentropic enthalpy drop
d. isentropic enthalpy drop to isothermal enthalpy drop
Answer  Explanation 

ANSWER: actual enthalpy drop to isentropic enthalpy drop

Explanation:
No explanation is available for this question!
6)   The quality of vapour at the exit of nozzle ___________ due to nozzle friction.

a. increases
b. decreases
c. does not change
d. unpredictable
Answer  Explanation 

ANSWER: increases

Explanation:
No explanation is available for this question!
7)   Consider the following (h-S) diagram of steam passing through a nozzle. Which is the correct path followed by steam when total friction loss occurs in divergent section.

Where,
p1 = pressure at the inlet of nozzle
p2 = pressure at the exit of nozzle
pt = pressure at the throat of nozzle

a. 1 – 2 – 3
b. 1 – 2 – 3'
c. 1 – 2 – 3''
d. None of the above
Answer  Explanation 

ANSWER: 1 – 2 – 3''

Explanation:
No explanation is available for this question!
8)   What is the relation between Velocity Coefficient (Cc) and Nozzle efficiency (ηn)?

a. Cc = (1/2) (ηn)
b. Cc = √(ηn)
c. Cc = (ηn)2
d. Cc = (ηn)3
Answer  Explanation 

ANSWER: Cc = √(ηn)

Explanation:
No explanation is available for this question!
9)   The ratio of actual mass flow rate (ṁa) to ideal mass flow rate (ṁi) is called as________

a. nozzle coefficient
b. coefficient of nozzle friction
c. coefficient of discharge
d. coefficient of mass
Answer  Explanation 

ANSWER: coefficient of discharge

Explanation:
No explanation is available for this question!
10)   Which of the following sentences are correct for steam turbine?

1. Steam turbine requires large floor area
2. Steam turbine is a rotary high speed machine
3. Steam turbine has low weight to power ratio
4. Steam turbine has more initial cost and maintenance cost

a. (1) and (2)
b. (2) and (3)
c. (3) and (4)
d. (1) and (4)
Answer  Explanation 

ANSWER: (2) and (3)

Explanation:
No explanation is available for this question!

Related Content

▲