Engineering Questions with Answers - Multiple Choice Questions

# Mechanical Operations MCQ’s – Leaf Filters

1 - Question

__________ is an exhaust gas driven compressor used to increase the power output.
a) Turbocharger
b) Sonic boom
c) Compressor
d) Rotor

Explanation: A turbocharger is an exhaust gas driven compressor used to increase the power output of an internal combustion engine by compressing air that is entering the engine.

2 - Question

________ consists of a row of rotor blades followed by a row of stator blades.
a) Centrifugal compressor
b) Axial compressor
c) Axial pump

Explanation: An axial compressor consists of a row of rotor blades followed by a row of stator blades and the working fluid traverses through these without significant change in radius.

3 - Question

The energy level of the fluid flowing through it is increased by the action of the __________

Explanation: The energy level of the fluid flowing through it is increased by the action of the rotor blades, which exert a torque on the fluid supplied by an external source.

4 - Question

An axial compressor is a relatively _________ pressure ratio turbomachine.
a) High
b) Low
c) Medium
d) Constant

Explanation: An axial compressor is a relatively low pressure ratio turbomachine with higher mass flow rate as compared to a centrifugal compressor.

5 - Question

Due to density variation from inlet to exit, the flow area _____________
a) Reduces
b) Increases
c) Remains same
d) Constant

Explanation: Due to density variation from inlet to exit, the compressor end walls have flare with flow area reducing from inlet to exit.

6 - Question

In an axial turbine, the kinetic energy of combustion gas is converted to mechanical power by _________
a) Shear action
b) Axial action
c) Impulse action
d) Tear action

Explanation: The kinetic energy of combustion gas is converted to mechanical power by the its impulse or reaction with a series of blades arranged around the circumference of a wheel or cylinder.

7 - Question

________ is one where the change in head is brought about primarily by a change in velocity.
a) Impulse turbine
b) Reaction turbine
c) Axial turbine

Explanation: An impulse turbine i.e. Pelton wheel or water wheel is one where the change in head is brought about primarily by a change in velocity.

8 - Question

Calculate NRe, if diameter is 12 m and impellor takes 20 rotations and density and viscosity are 1.20 and 200?
a) 15.50
b) 17.28
c) 10.25
d) 8.52

Explanation: As NRe is given as (122*20*1.20/200) = 17.28.

9 - Question

Calculate NFr, if impellor takes 15 rotations and 1.2 m in diameter?
a) 7.88
b) 7.36
c) 8.38
d) 5.50

Explanation: As NFr = (225*1.2/g) = 225*1.2/32.2 = 8.38.

10 - Question

Calculate power, if Q is 4.50 m3/s and at a height of 2 m and consider water as fluid?
a) 600
b) 900
c) 100
d) 500