Explore topic-wise MCQs in Thermal Engineering.

This section includes 14 Mcqs, each offering curated multiple-choice questions to sharpen your Thermal Engineering knowledge and support exam preparation. Choose a topic below to get started.

1.

Determine the velocity of steam at throat if the discharge through the nozzle is maximum. Steam enters the nozzle in dry and saturated state and at 11 bar.

A. 455.45 m/s
B. 625.32 m/s
C. 545.87 m/s
D. 325.65 m/s
Answer» B. 625.32 m/s
2.

The maximum mass flow through a steam nozzle is independent of _____

A. Initial pressure
B. Initial density
C. Final pressure
D. Throat area
Answer» D. Throat area
3.

Steam enters a nozzle at 14 bar and 200 C. Determine the discharge if the discharge through the nozzle is maximum. Take the area of throat as 0.002 m2.

A. 3.95 kg/s
B. 4.18 kg/s
C. 2.36 kg/s
D. 1.65 kg/s
Answer» C. 2.36 kg/s
4.

Calculate the throat pressure if the dry and saturated steam enters a nozzle at 15 bar. Consider the discharge through the nozzle maximum.

A. 8.66 bar
B. 7.58 bar
C. 5.65 bar
D. 2.36 bar
Answer» B. 7.58 bar
5.

Which of the following equations represent the correct critical pressure ratio?

A. ( frac{P_1}{P_2} = ( frac{2}{n+1})^ frac{n}{n-1} )
B. ( frac{P_2}{P_1} = ( frac{2}{n-1})^ frac{n}{n-1} )
C. ( frac{P_2}{P_1} = ( frac{2}{n+1})^ frac{n}{n-1} )
D. ( frac{P_2}{P_1} = ( frac{2}{n+1})^ frac{n}{n+1} )
Answer» D. ( frac{P_2}{P_1} = ( frac{2}{n+1})^ frac{n}{n+1} )
6.

Dry saturated steam enters a steam nozzle at 12 bar and 200 C and leaves at 2 bar. If the exit area is 0.00197 m2, determine the mass flow rate of steam.

A. 1 kg/s
B. 2 kg/s
C. 3 kg/s
D. 4 kg/s
Answer» C. 3 kg/s
7.

Final velocity of steam passing thorough a nozzle is found out to be 586 m/s. The pressure of steam at inlet is 15 bar and is dry and saturated. The exit pressure is 2 bar. Determine the dryness fraction of the steam when it leaves the nozzle.

A. 0.79
B. 0.96
C. 0.88
D. 0.81
Answer» C. 0.88
8.

Dry and saturated steam enters a nozzle at 11 bar and leaves at 2 bar. What minimum exit area should the nozzle have if the steam flow of 2 kg/s is to be maintained?

A. 0.00365 m<sup>2</sup>
B. 0.02156 m<sup>2</sup>
C. 0.00312 m<sup>2</sup>
D. 0.00228 m<sup>2</sup>
Answer» E.
9.

Steam entering a nozzle at 15 bar and 350 C is discharged at 1 bar. If the inlet velocity of the steam is 50 m/s, determine the exit velocity.

A. 785 m/s
B. 365 m/s
C. 565 m/s
D. 475 m/s
Answer» D. 475 m/s
10.

Steam at a temperature 200 C and pressure 4 bar enters a steam nozzles and is discharged at 1 bar pressure. Determine the exit velocity of steam if the inlet velocity is negligible.

A. 500 m/s
B. 720 m/s
C. 580 m/s
D. 750 m/s
Answer» C. 580 m/s
11.

The steam flow though nozzle is considered to be _____

A. adiabatic
B. isobaric
C. isothermal
D. isochoric
Answer» B. isobaric
12.

The smallest section of a steam nozzle is called _____

A. maw
B. neck
C. throat
D. muzzle
Answer» D. muzzle
13.

Which of the following statements about steam nozzles is FALSE?

A. It converts the heat energy of the steam into kinetic energy
B. It has a varying cross section
C. The smallest section is called throat
D. The pressure at the outlet is more than at the inlet
Answer» E.
14.

A steam nozzle is a passage of varying cross section through which the kinetic energy of steam is converted into heat energy.

A. True
B. False
Answer» C.