Explore topic-wise MCQs in Mechanical Engineering Questions.

This section includes 56 Mcqs, each offering curated multiple-choice questions to sharpen your Mechanical Engineering Questions knowledge and support exam preparation. Choose a topic below to get started.

1.

The blade passages in a compressor are ________
A. converging
B. diverging
C. constant
D. unpredictable
Answer» C. constant
Discussion
2.

Angular momentum of gas in the free vortex of vaneless diffuser ___________.
A. increases
B. decreases
C. remains constant
D. becomes unpredictable
Answer» D. becomes unpredictable
Discussion
3.

The pressure of water is atmospheric and remains constant while passing over the runner in __________ .
A. Impulse turbine
B. Reaction turbine
C. Both a. and b.
D. None of the above
Answer» B. Reaction turbine
Discussion
4.

The product of force (F) and time (t) is called as________.
A. momentum
B. work done
C. impulse
D. pressure
Answer» D. pressure
Discussion
5.

___________ pump is also called as velocity pump.
A. Reciprocating
B. Rotary displacement
C. Centrifugal
D. Screw
Answer» D. Screw
Discussion
6.

Which of the following is/are example/s of rotary displacement pumps?
A. Gear pump
B. Vane pump
C. Rotary piston pump
D. All of the above
Answer» E.
Discussion
7.

What is the formula for forces exerted by fluid on a body?
A. (Rate of momentum in) x (Rate of momentum out)
B. (Rate of momentum in) – (Rate of momentum out)
C. (Rate of momentum in) + (Rate of momentum out)
D. None of the above
Answer» C. (Rate of momentum in) + (Rate of momentum out)
Discussion
8.

Rotary displacement pumps are suitable for handling ________.
A. oils
B. gritty liquids
C. both oils as well as gritty liquids
D. None of the above
Answer» B. gritty liquids
Discussion
9.

__________ turbines are also called as parallel flow turbine.
A. Radial flow
B. Axial flow
C. Both radial flow and axial flow
D. None of the above
Answer» C. Both radial flow and axial flow
Discussion
10.

Which of the following is NOT a type of rotary compressor?
A. Positive displacement type of compressor
B. Steady flow compressor
C. Both a. and b.
D. None of the above
Answer» E.
Discussion
11.

An axial flow compressors have _______.
A. a drum type rotor
B. a disc type rotor
C. a drum type rotor or a disc type rotor
D. none of the above
Answer» D. none of the above
Discussion
12.

The mass flow rate of air compressed in axial flow compressor is _____________centrifugal compressor.
A. lower than
B. higher than
C. same as
D. unpredictable
Answer» C. same as
Discussion
13.

The function of _________ is to convert high kinetic energy of gases into pressure energy.
A. impeller
B. diffuser
C. casing
D. None of the above
Answer» C. casing
Discussion
14.

How is the variation of air velocity while passing through impeller followed by diffuser in centrifugal compressor?
A. Air velocity goes no increasing in impeller followed by diffuser
B. Air velocity goes no decreasing in impeller followed by diffuser
C. Air velocity increases in impeller and then decreases in diffuser
D. Air velocity decreases in impeller and then increases in diffuser
Answer» D. Air velocity decreases in impeller and then increases in diffuser
Discussion
15.

A pair of fixed blade and rotor blade in axial flow compressor is called as _________.
A. step
B. pair
C. stage
D. state
Answer» D. state
Discussion
16.

Meridonial velocity is the resultant of _____________ components of fluid velocity.
A. radial and tangential
B. tangential and axial
C. radial and axial
D. unpredictable
Answer» D. unpredictable
Discussion
17.

________ blades are attached to the rotor or spindle.
A. Fixed
B. Moving
C. Both fixed and moving
D. None of the above
Answer» C. Both fixed and moving
Discussion
18.

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» C. steam area
Discussion
19.

The quality of vapour at the exit of nozzle ___________ due to nozzle friction.
A. increases
B. decreases
C. does not change
D. unpredictable
Answer» B. decreases
Discussion
20.

The water from runner in reaction turbine is discharged into tail race through a draft tube which has ____________ cross sectional area.
A. constant
B. gradually decreasing
C. gradually increasing
D. uneven
Answer» D. uneven
Discussion
21.

Generally, the value of specific speed of Kaplan turbine is _____________ that of the Pelton turbine.
A. lower than
B. higher than
C. same as
D. unpredictable
Answer» C. same as
Discussion
22.

In which type of reaction turbine does the water flow in radial direction at the outer periphery of runner and leave at the centre in the direction parallel to the axis of rotation of runner?
A. Radial flow turbine
B. Axial flow turbine
C. Mixed flow turbine
D. All of the above
Answer» D. All of the above
Discussion
23.

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» C. isothermal enthalpy drop to isentropic enthalpy drop
Discussion
24.

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» E.
Discussion
25.

Which of the following is NOT a type of positive displacement pumps?
A. Reciprocating pump
B. Rotary displacement pump
C. Centrifugal pump
D. None of the above
Answer» D. None of the above
Discussion
26.

The radial force in rotodynamic machine, which is developed by rate of change of momentum in radial velocity, is taken care by__________.
A. journal bearing
B. radial thrust bearing
C. both a. and b.
D. none of the above
Answer» B. radial thrust bearing
Discussion
27.

Pump transfers the mechanical energy of a motor or of an engine into _________ of a fluid.
A. pressure energy
B. kinetic energy
C. either pressure energy or kinetic energy
D. pressure energy, kinetic energy or both
Answer» E.
Discussion
28.

The energy of water entering the reaction turbine is _______
A. fully the kinetic energy
B. fully the pressure energy
C. partly the pressure energy and partly the kinetic energy
D. unpredictable
Answer» D. unpredictable
Discussion
29.

In which turbine the pressure energy of water is first converted into kinetic energy by means of nozzle kept close to the runner?
A. Impulse turbine
B. Reaction turbine
C. Both a. and b.
D. None of the above
Answer» B. Reaction turbine
Discussion
30.

_______________ components of fluid velocity have the responsibility of the transportation of fluid through the machine.
A. Radial and tangential
B. Tangential and axial
C. Radial and axial
D. None of the existing
Answer» D. None of the existing
Discussion
31.

Which of the following is an example of impulse turbine?
A. Propeller turbine
B. Francis turbine
C. Kaplan turbine
D. Pelton wheel
Answer» E.
Discussion
32.

The runner of __________ turbine always be under pressure of above atmospheric
A. Turgo
B. Girand
C. Kaplan
D. None of the above
Answer» D. None of the above
Discussion
33.

Gross head is the difference between __________.
A. head race and tail race
B. head race and net head
C. head race and friction losses
D. net head and friction losses
Answer» B. head race and net head
Discussion
34.

What is the head of water available at turbine inlet in hydro-electric power plant called?
A. head race
B. tail race
C. gross head
D. net head
Answer» E.
Discussion
35.

The basic principle of operation of axial flow compressor is _______that of the centrifugal compressor.
A. same as
B. totally different than
Answer» B. totally different than
Discussion
36.

The gates of aerofoil section in between the outer and inner ring of guide wheel are called as ________.
A. guide gates
B. guide vanes
C. scrolling gates
D. scrolling vanes
Answer» C. scrolling gates
Discussion
37.

Which of the following components of reaction turbine increases the head on the turbine by an amount equal to the height of runner outlet above the tail race?
A. Scroll casing
B. Guide vanes
C. Moving vanes
D. Draft tube
Answer» E.
Discussion
38.

Which component of fluid velocity is responsible for transmission of power through rotodynamic machine?
A. Radial
B. Axial
C. Tangential
D. None of the above
Answer» D. None of the above
Discussion
39.

What is runaway speed of the runner of Pelton wheel?
A. maximum unsafe speed of the runner due to sudden increase in load on turbine
B. minimum safe speed of the runner due to sudden increase in load on turbine
C. maximum unsafe speed of the runner due to sudden decrease in load on turbine
D. minimum safe speed of the runner due to sudden decrease in load on turbine
Answer» D. minimum safe speed of the runner due to sudden decrease in load on turbine
Discussion
40.

In reaction turbine work is done_______________.
A. totally due to change in kinetic energy of jet
B. totally due to change in pressure head
C. mostly due to change in pressure head and small amount of work is due to change in kinetic energy
D. mostly due to change in kinetic energy and small amount of work is due to change in pressure head
Answer» D. mostly due to change in kinetic energy and small amount of work is due to change in pressure head
Discussion
41.

As the reaction turbine works on the principle of impulse and reaction, it follows the law of ________.
A. impulse momentum
B. angular momentum
C. both a. and b.
D. none of the above
Answer» C. both a. and b.
Discussion
42.

In which type of turbine, the runner needs to be run full of water?
A. Impulse turbine
B. Reaction turbine
C. Both a. and b.
D. None of the above
Answer» C. Both a. and b.
Discussion
43.

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» B. (Blade velocity) / (Steam velocity at exit)
Discussion
44.

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» C. (3) and (4)
Discussion
45.

The process of filling the liquid into the suction pipe and pump casing upto the level of delivery valve is called as _________.
A. filling
B. pumping
C. priming
D. leveling
Answer» D. leveling
Discussion
46.

Discharge capacity of the reciprocating pump is __________ that of the centrifugal pump.
A. higher than
B. lower than
C. same as
D. unpredictable
Answer» C. same as
Discussion
47.

Which pump is more suitable for an application where very high pressure is required to be developed at moderate discharge?
A. Reciprocating pump
B. Centrifugal pump
C. Turbine
D. None of the above
Answer» B. Centrifugal pump
Discussion
48.

Which of the following centrifugal pumps has higher specific speed than the others?
A. Axial flow
B. Radial flow
C. Mixed flow
D. All have same specific speed
Answer» B. Radial flow
Discussion
49.

The volute pumps and vortex volute pumps are __________ pumps with _________ shaft.
A. multistage, horizontal
B. multistage, vertical
C. single stage, horizontal
D. single stage, vertical
Answer» D. single stage, vertical
Discussion
50.

What is the effect of increasing flow coefficient (Φ) in an axial flow compressor on blade loading coefficient (Ψ)?
A. Blade loading coefficient (Ψ) increases
B. Blade loading coefficient (Ψ) decreases
C. Blade loading coefficient (Ψ) remains constant
D. Unpredictable
Answer» C. Blade loading coefficient (Ψ) remains constant
Discussion