Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
On what principal does a reciprocating pump work?
A)
Centrifugal force
B)
Rotation of impeller to develop lifting pressure
C)
Create a reciprocating motion by sucking and discharge of fluid by using piston
D)
Forced vortex flow
Option C is correct: Create a reciprocating motion by sucking and discharge of fluid by using piston.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
Centrifugal pump is started with its delivery valve-
A)
kept fully closed
B)
kept fully opened
C)
irrespective of any position
D)
kept 50% opened
Option A is correct: kept fully closed.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
Governing mechanism used in case of Francis and Kaplan turbines is-
A)
Guide vane
B)
Nozzle needle
C)
Control valve
D)
Dam gates
Option A is correct: Guide vane.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
Cavitation in hydraulic turbine results in-
A)
Noise and vibration
B)
reduction and discharge
C)
drop in output and efficiency
D)
rough surfaces
Option C is correct: drop in output and efficiency.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
The clearance volume of air compressor is kept minimum because-
A)
It allows maximum compression to be achieved
B)
It greatly affects volumetric efficiency
C)
It results in minimum work
D)
It permits isothermal compression
Option B is correct: It greatly affects volumetric efficiency.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
The creep in belt drive is due to-
A)
Power fluctuation
B)
Thickness of the belt
C)
Unequal tension in tight and slack side of the belt
D)
Equal size of the pulleys
Option C is correct: Unequal tension in tight and slack side of the belt.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
The specific speed of a turbine is the speed of such a turbine, identical with a given turbine, which-
A)
Develops unit power under unit head
B)
Develops unit power under unit discharge
C)
Develops unit speed under unit head
D)
Delivers unit discharge under unit head
Option A is correct: Develops unit power under unit head.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
Governing mechanism used in case of pelton wheel turbine is-
A)
Guide vane
B)
Nozzle needle
C)
Control valve
D)
Dam gates
Option B is correct: Nozzle needle.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
The governing of water turbine refers to-
A)
Maintain the discharge constant under all conditions
B)
Maintain the speed constant under all conditions
C)
Allow the turbine to run at runaway speed
D)
Maintain the power constant under all conditions
Option B is correct: Maintain the speed constant under all conditions.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
Which of the following governor can possibly be an isochronous governor?
A)
Watt governor
B)
Hunting governor
C)
Porter governor
D)
Hartnell governor
Option D is correct: Hartnell governor.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
Which is the desirable physical property of a refrigerant?
A)
Toxic
B)
Explosive
C)
Low boiling point
D)
High freezing point
Option C is correct: Low boiling point.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
In a hydraulic crane, the component mainly responsible for lifting is-
A)
Boom
B)
Counter-weights
C)
Jib
D)
Rotex Gear
Option A is correct: Boom.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
The ratio of power produced by the turbine to the energy actually supplied by the turbine is-
A)
Mechanical efficiency of the turbine
B)
Hydraulic efficiency of the turbine
C)
Overall efficiency of the turbine
D)
Relative efficiency of the turbine
Option A is correct: Mechanical efficiency of the turbine.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
When a centrifugal pump casing is filled with liquid before it is started, it is called as-
A)
Adiabatic expansion
B)
Priming
C)
Adiabatic compression
D)
Isentropic expansion
Option B is correct: Priming.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
Intercooling in gas turbine results in-
A)
Increase in net output but decrease in thermal efficiency
B)
Increase in thermal efficiency but decrease in net output
C)
Increase in both thermal efficiency and net output
D)
Decrease in both thermal efficiency and net output
Option A is correct: Increase in net output but decrease in thermal efficiency.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
On what principal does a centrifugal pump work?
A)
Centrifugal force
B)
Rotation of impeller to develop lifting pressure
C)
Create a reciprocating motion by sucking and discharge of fluid by using piston
D)
Forced vortex flow
Option A is correct: Centrifugal force.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
Which one of the following drives is used for transmitting power without slip?
A)
Belt drives
B)
Rope drives
C)
Cone pulleys
D)
Chain drives
Option D is correct: Chain drives.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
The term ‘effort of governor’ refers to-
A)
Centrifugal force of balls
B)
useful power developed
C)
force acting on sleeve for given percentage change of speed
D)
minimum force required on sleeve for percentage change of speed
Option C is correct: force acting on sleeve for given percentage change of speed.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
A portable drilling machine is specified by-
A)
the size of the job it can hold
B)
maximum diameter of drill it can hold
C)
spindle speeds and feeds
D)
maximum spindle travel
Option B is correct: maximum diameter of drill it can hold.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
The air-fuel ratio in gas turbines is of the order of-
A)
7:1
B)
15:1
C)
30:1
D)
50:1
Option D is correct: 50:1.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
The comfort conditions in air conditioning system are defined by-
A)
22°C dry bulb temperature and 60% relative humidity
B)
25°C dry bulb temperature and 100% relative humidity
C)
20°C dry bulb temperature and 75% relative humidity
D)
15°C dry bulb temperature and 80% relative humidity
Option A is correct: 22°C dry bulb temperature and 60% relative humidity.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
For welding overhead joints in horizontal plane, following technique of gas welding is used:
A)
forehand
B)
back hand
C)
straight hand
D)
inclined hand
Option A is correct: forehand.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
To avoid cavitation in centrifugal pumps-
A)
suction pressure should be low
B)
delivery pressure should be low
C)
suction pressure should be high
D)
delivery pressure should be high
Option C is correct: suction pressure should be high.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
The main purpose of multi-stage air compression with intercooling is-
A)
Increase in maximum temperature of cycle
B)
Expansion of refrigerant near to saturated liquid line
C)
Compression of refrigerant away from saturated vapour line
D)
Reduction in work input for same pressure ratio
Option D is correct: Reduction in work input for same pressure ratio.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
A centrifugal compressor works on the principle of-
A)
Conversion of pressure energy into kinetic energy
B)
Conversion of kinetic energy into pressure energy
C)
Centripetal action
D)
Generating pressure directly
Option B is correct: Conversion of kinetic energy into pressure energy.
