Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
The pressure ratio in gas turbines is of the order of-
A)
2:1
B)
4:1
C)
6:1
D)
12:1
Option C is correct: 6:1.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
Too low welding current in arc welding would result in-
A)
excessive piling up of weld metal, poor penetration, wasted electrodes
B)
excessive spatter, under cutting along edges, irregular deposits, wasted Electrodes
C)
too small bead, weak weld and wasted electrodes
D)
excessive piling up of weld metal, overlapping, without penetration of edges, wasted electrodes
Option C is correct: too small bead, weak weld and wasted electrodes.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
For non-parallel non-intersecting shafts, power can be transmitted with the help of-
A)
Pair of helical gear
B)
Pair of spur gear
C)
Pair of spiral gear
D)
Oldham coupling
Option A is correct: Pair of helical gear.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
A turbine pump is basically a centrifugal pump equipped additionally with-
A)
adjustable blades
B)
backward curved blades
C)
vaned diffusion casing
D)
inlet guide blades
Option D is correct: inlet guide blades.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
Gas turbines for power generation are normally used-
A)
to supply based load requirements
B)
to supply peak load requirements
C)
to enable starting of thermal power plant
D)
when other sources of power fail
Option B is correct: to supply peak load requirements.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
Role of pump testing is-
A)
To measure pressure, flow rates and speeds
B)
To measure input and output power
C)
To measure noise emissions, strength levels and vibrations
D)
All of the above
Option D is correct: All of the above.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
The function of a governor is to-
A)
store energy and give up whenever required
B)
regulate the speed during one cycle of a prime mover
C)
decrease variation of speed
D)
adjust variation of speed by varying the input to the engine
Option D is correct: adjust variation of speed by varying the input to the engine.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
Break-even analysis shows profit when-
A)
sales revenue > total cost (i.e. fixed cost + variable cost)
B)
sales revenue = total cost (i.e. fixed cost + variable cost)
C)
sales revenue < total cost (i.e. fixed cost + variable cost)
D)
variable cost < fixed cost
Option A is correct: sales revenue > total cost (i.e. fixed cost + variable cost).
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
Grinding operation is used for-
A)
removing material
B)
shaping
C)
dressing
D)
finishing
Option D is correct: finishing.
Departmental (other) • 2024 • Engineering Paper-II (Mechanical Engineer Under Electrical Wing)
If requirement of Net Positive Suction Head (NPSH) of a centrifugal pump is not satisfied-
A)
Pump will not develop head
B)
Pump will be cavitated
C)
pump efficiency will be low
D)
no flow will take place
Option B is correct: Pump will be cavitated.
Departmental (other) • 2024 • Engineering Paper-II
The heat produced (in keals) in a resistance R ohms when a current I amperes flows through it for t seconds is given by
A)
I²Rt
B)
I²Rt/(4.2x10³)
C)
I²Rt x 4.2
D)
IRt/J
Option B is correct: I²Rt/(4.2x10³).
Departmental (other) • 2024 • Engineering Paper-II
Lenz’s law is related to
A)
the direction of magnetic field
B)
the direction of motion of conductor
C)
the direction of the induced current
D)
both (a) and (b)
Option C is correct: the direction of the induced current.
Departmental (other) • 2024 • Engineering Paper-II
The power factor of an a.c. circuit is given by
A)
X/R
B)
Z/R
C)
RX
D)
R/Z
Option D is correct: R/Z.
Departmental (other) • 2024 • Engineering Paper-II
When magnetic flux linking a conductor changes
A)
an e.m.f is always induced
B)
a current is always induced
C)
both e.m.f and current are always induced
D)
neither e.m.f nor current are induced
Option A is correct: an e.m.f is always induced.
Departmental (other) • 2024 • Engineering Paper-II
The e.m.f induced in a coil of N turns is given by
A)
dΦ/dt
B)
NdΦ/dt
C)
-NdΦ/dt
D)
Ndt/dΦ
Option C is correct: -NdΦ/dt.
Departmental (other) • 2024 • Engineering Paper-II
The skin effect increases the
A)
resistance of the line
B)
inductance of the line
C)
capacitance of the line
D)
inductance and capacitance line
Option A is correct: resistance of the line.
Departmental (other) • 2024 • Engineering Paper-II
Reactive power in an a.c circuit is
A)
measured by a wattmeter
B)
the useful power
C)
consumed in the circuit
D)
a liability on the circuit
Option D is correct: a liability on the circuit.
Departmental (other) • 2024 • Engineering Paper-II
The supply voltage of a consumer is 220VAC and his internal wiring is protected by 9A fuse. How many 60W bulb in parallel can be turned on simultaneously without breaking the fuse?
A)
33 nos
B)
44 nos
C)
22 nos
D)
20 nos
Option A is correct: 33 nos.
Departmental (other) • 2024 • Engineering Paper-II
The capacitance of a transmission line is neglected in case of
A)
medium line
B)
long line
C)
short line
D)
extra long line
Option C is correct: short line.
Departmental (other) • 2024 • Engineering Paper-II
Corona effect
A)
produces ozone gas
B)
reduces transmission efficiency
C)
causes line to draw non-sinusoidal current
D)
all the above
Option D is correct: all the above.
Departmental (other) • 2024 • Engineering Paper-II
The speed at which a 6-pole alternator should be driven to generate 50 cycles per second is
A)
1500 rp.m
B)
1000 rp.m
C)
800rp.m
D)
500rp.m
Option A is correct: 1500 rp.m.
Departmental (other) • 2024 • Engineering Paper-II
The frequency of e.m.f. generated in an 8 pole alternator running at 900 r.p.m is
A)
50Hz
B)
60 Hz
C)
120Hz
D)
140 Hz
Option A is correct: 50Hz.
Departmental (other) • 2024 • Engineering Paper-II
The resistance of a straight conductor is independent of
A)
temperature
B)
material
C)
cross-sectional area
D)
shape of cross-section
Option D is correct: shape of cross-section.
Departmental (other) • 2024 • Engineering Paper-II
Mesh current analysis is based on
A)
Kirchhoff’s current law
B)
Kirchhoff’s voltage law
C)
Maxwell’s law
D)
Norton’s law
Option B is correct: Kirchhoff’s voltage law.
Departmental (other) • 2024 • Engineering Paper-II
Inductive reactance is measured in ohms because it
A)
reduces the amplitude of the alternating current
B)
increases the amplitude of alternating current
C)
increases the amplitude of direct current
D)
has a back e.m.f opposing a steady direct current
Option A is correct: reduces the amplitude of the alternating current.
