Aptransco Sub
Engineer PREVIOUS Question Papers
(1)The two windings of a transformer is
(A) conductively linked.
(A) conductively linked.
(B) inductively
linked.
(C) not linked at all.
(C) not linked at all.
(D) electrically
linked.
Ans : B
Ans : B
(2) The d.c. should always be started with load series
motor because
(A) at no load, it will rotate at dangerously high speed.
(B) it will fail to start.
(C) it will not develop high starting torque.
(D) all are true.
Ans: A
(A) at no load, it will rotate at dangerously high speed.
(B) it will fail to start.
(C) it will not develop high starting torque.
(D) all are true.
Ans: A
(3) The frequency of the rotor current in a 3 phase
50 Hz, 4 pole induction motor at full load speed is about
(A) 50 Hz.
(A) 50 Hz.
(B) 20 Hz.
(C) 2 Hz.
(C) 2 Hz.
(D) Zero.
Ans: C
Ans: C
(4) The power factor of a squirrel cage induction
motor is
(A) low at light load only.
(B) low at heavy load only.
(C) low at light and heavy load both.
(D) low at rated load only.
Ans: A
(A) low at light load only.
(B) low at heavy load only.
(C) low at light and heavy load both.
(D) low at rated load only.
Ans: A
(5) The generation voltage is usually
(A) between 11 KV and 33 KV.
(A) between 11 KV and 33 KV.
(B) between 132 KV
and 400 KV.
(C) between 400 KV and 700 KV.
(C) between 400 KV and 700 KV.
(D) None of the above.
Ans: A
Ans: A
(6) When a synchronous motor is running at
synchronous speed, the damper winding
produces
(A) damping torque.
(B) eddy current torque.
(C) torque aiding the developed torque.
(D) no torque.
Ans: D
produces
(A) damping torque.
(B) eddy current torque.
(C) torque aiding the developed torque.
(D) no torque.
Ans: D
(7) If a transformer primary is energised from a
square wave voltage source, its output
voltage will be
(A) A square wave.
voltage will be
(A) A square wave.
(B) A sine wave.
(C) A triangular wave.
(C) A triangular wave.
(D) A pulse wave.
Ans: A
Ans: A
(8) In a d.c. series motor the electromagnetic
torque developed is proportional to
(A) Ia
(B) (Ia)2
(A) Ia
(B) (Ia)2
(C) 1/Ia
(D) 1/(Ia)2
Ans: B
(9) In a d.c. machine, the armature mmf is
(A) stationary w.r.t. armature.
(A) stationary w.r.t. armature.
(B) rotating w.r.t.
field.
(C) stationary w.r.t.
field.
(D) rotating w.r.t.
brushes.
Ans: C
Ans: C
(10)Which of the following is usually not the
generating voltage ?
(A) 6.6 kV
(B) 9.9 kV
(C) 11kV
(D) 13.2 kV.
Ans: B
(11) Boosters are basically
(A) inductors
(B) capacitors
(C) transformers
(D) synchronous motors
Ans: C
(11)Which of the following is not the distribution
system normally used
(A) 3 phase-4 wire
(B) 3 phase-3 wire
(C) Single phase – 3 wire
(D) Single phase -4 wire.
Ans: D
(12) Conductors for high voltage transmission lines
are suspended from towers
(A) to reduce clearance
from ground
(B) to increase clearance
from ground
(C) to reduce wind and
snow loads
(D) to take care of
extension in length during summer.
Ans: B
(13)Transmission efficiency increases as
(A) voltage and power
factor both increase
(B) voltage and power
factor both decrease
(C) voltage increases but
power factor decreases
(D) voltage decreases but
power factor increases.
Ans: A
(14)In overhead transmission lines the effect of
capacitance can be neglected when the length of line is less than
(A) 200 km
(B) 160 km
(C) 100 km
(D) 80 km.
Ans: D
(15) Skin effect depends on
(A) size of the conductor
(B) frequency of the
current
(C) resistivity of the
conductor material
(D) all of the above.
Ans: D
(16) Instrument is a device for determining
(a) the magnitude of a
quantity
(b) the physics of a
variable
(c) either of the above
(d) both (a) and (b)
(17) Electronic instruments are preferred because
they have
(a) no indicating part
(b) low resistance in
parallel circuit
(c) very fast response
(d) high resistance in
series circuit
(e) no passive elements.
(18) An accurate voltmeter must have an internal
impedance of
(a) very low value
(b) low value
(c) medium value
(d) very high value
(19) The insulation resistance of a transformer winding
can be easily measured with
(a) Wheatstone bridge
(b) megger
(c) Kelvin bridge
(d) voltmeter
(20) A 100 V voltmeter has full-scale accuracy of
5%. At its reading of 50 V it will give an error of
(a) 10%
(b) 5%
(c) 2.5%
(d) 1.25%
(21) An analog instrument has output
(a) Pulsating in nature
(b) Sinusoidal in nature
(c) Which is continuous
function of time and bears a constant relation to its input
(d) Independent of the
input quantity
(22) Which of the following instrument is suitable
for measuring both a.c. and d.c.
quantities.
(a) permanent magnet
moving coil ammeter.
(b) Induction type
ammeter.
(c) Quadrant
electrometer.
(d) Moving iron repulsion
type ammeter.
(e) Moving iron
attraction type voltmeter.
Ans: B
(23) For a line voltage V and regulation of a
transmission line R
(24) The temperature of resistance furnaces can be
controlled by changing the:
(A) applied voltage
(A) applied voltage
(B) number of
heating elements
(C) circuit configuration
(C) circuit configuration
(D) All of the
above
Ans: D
Ans: D
(25) A single phase Hysteresis motor
(A) can run at synchronous speed only
(B) can run at sub synchronous speed only
(C) can run at synchronous and super synchronous speed
(D) can run at synchronous and sub synchronous speed
(A) can run at synchronous speed only
(B) can run at sub synchronous speed only
(C) can run at synchronous and super synchronous speed
(D) can run at synchronous and sub synchronous speed
Ans: A
(26) The armature of a dc machine is laminated to
reduce:
(A) Eddy current loss
(A) Eddy current loss
(B) Hysteresis loss
(C) copper losses
(C) copper losses
(D) friction and
windage losses
Ans: A
Ans: A
(26) No load current in a transformer:
(A) lags the applied voltage by 90°
(B) lags the applied voltage by somewhat less than 90°
(C) leads the applied voltage by 90°
(D) leads the applied voltage by somewhat less than 90°
Ans: B
(A) lags the applied voltage by 90°
(B) lags the applied voltage by somewhat less than 90°
(C) leads the applied voltage by 90°
(D) leads the applied voltage by somewhat less than 90°
Ans: B
(27) Fleming’s left hand rule is applicable to ?
a) dc
generator
b) dc motor
c) alternator
d) Transformer
ANS: (b)
(28) Which of the following power plants is the
least reliable ?
a) wind
b) tidal
c)
geothermal d)
solor
ANS: (a)
29) Which of the following power plants is the most
reliable ?
a) diesel
b) Hydro-electric
c) steam
d) tidal
ANS: (b)
(30) Zener diodes , when used as voltage standards
?
a) are forward biased
b) are reverse biased
c) cover a wide range of
current
d) operate in breakdown strength
e) all of above except
(a)
ANS : (e)
No comments:
Post a Comment