1. The failure % of electric motor is
higher due to
(a) Bearing failure
(b) Insulation failure
(c) Over loading
(d) None
(a) Bearing failure
(b) Insulation failure
(c) Over loading
(d) None
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2. In case of induction motor, Star I Delta starter is used
(a) To prevent the motor from tripping (b) Because it connects motor automatically in Delta winding (c) To save the cost of H R C fuses (d) None |
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3.
When two batteries are connected in parallel, it should be ensured that
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(a) they have same e.m.f
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(b) they have same make
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(c) they have same ampere-hour
capacity
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(d) they have identical internal
resistance
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4.
Which of the following is an AC motor?
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(a) Slip ring motor
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(b) Synchronous motor
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(c) Squirrel cage Induction
motor
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(d) All of the above
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5. In Transformer, oil is used for
(a) Cooling the Transformer
(b) Providing insulation to Transformer winding and for cooling the Transformer
(c) Lubricating the Transformer
(d) None
(a) Cooling the Transformer
(b) Providing insulation to Transformer winding and for cooling the Transformer
(c) Lubricating the Transformer
(d) None
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6.
Which of the following information available on name plate of a motor?
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(a) HP rating
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(b) RPM
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(c) Frame model
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(d) All the above
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7.
Two types of earthings are provided: (a) Equipment earthing and (b) Neutral
point
earthing. Equipment earthing is provided for
(a) Safety of human being
(b) Safety of equipments
(c) Safety of starters and cables
(d) None
(b) Safety of equipments
(c) Safety of starters and cables
(d) None
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8.
Conservator is used
(a) to take up the expansion of oil due to temperature rise. (b) to act as oil storage. (c) for better cooling of the transformer. (d) none of the above. |
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9. The three phase squirrel cage
induction motor takes approximately its full load current _______ times the
h.p. of the motor.
(a) double
(b) one and half
(c) three
(d) six
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10.
If the thickness of laminations is increased, then
(a) the eddy current loss decreases. (b) the eddy current loss increases. (c) the hysteresis loss decreases. (d) the hysteresis loss increases. |
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11. If
alignment is not proper,
(a) fuses will blow. (b) motor will draw high current. (c) there will be vibrations on driver and driven unit. (d) None. |
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12. The synchronous speed of a motor with 6
poles and operating at 50 Hz frequency is ___.
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(a) 1500
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(b) 1000
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(c) 3000
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(d) 750
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13. A 3-phase, 50 Hz, 8-pole
squirrel cage induction motor will run at a speed
(a) < 750 r.p.m. (b) > 750 r.p.m. but < 1000 r.p.m. (c) > 1000 r.p.m. but < 1500 r.p.m. (d) > 1500 r.p.m. |
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14.
D.C. motor starters are used
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(a) to increase the starting
torque.
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(b) to limit the starting
current.
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(c) both (a) and (b).
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(d) none of the above.
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15.
If three 10µF capacitors are connected in parallel, the net capacitance is
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(a) 10/3µF
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(b) 30µF
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(c) 3/10µF
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(d) 60µF
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16. The numbers of slip rings of a
single-phase and three-phase converters are respectively
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(a) 1 and 3.
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(b) 2 and 3.
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(c) 2 and 6.
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(d) 1 and 6.
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17. Buchholz relay is placed
(a) in between the conservation and the breather. (b) in between the tank and the conservator. (c) in between the h.v. winding and the bushing. (d) in between the l.v. winding and the bushing. |
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18. Use of ELCB is advisable for
(a) human safety. (b) Ease to reset when trips. (c) Protecting from short-circuit. (d) None |
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19. What value
of capacitance will give approx. same reactance as an inductor of 1 H at 50
Hz?
(a) 10 micro-Farad. (b) 1 micro-Farad. (c) 1 Farad. (d) 10 Farad. |
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20. High battery voltage can be
obtained by
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(a) connecting cells in series
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(b) connecting cells in parallel
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(c) using large size cells
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(d) increasing quantity of electrolyte
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21. The transformer in which the
winding is surrounded by the core is known as
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(a) shell type
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(b) core type
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(c) tertiary type
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(d) none of the above A,B,C
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22.
Unit of magnetic flux is
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(a) Weber
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(b) Ampere - turn
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(c) Tesla
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(d) Coulomb
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23. Lamps of 40 W, 100 W and 200 W
are connected in different phases of a 3 — phase 4 — wire supply. If the
neutral wire breaks, the lamp likely to fuse first will be
(a) 200W
(b) 100W (c) 40 W (d) All lamps |
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24. What of the following is
commonly used for extending the range of an AC ammeter?
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(a) a current transformer
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(b) a capacitor
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(c) a shunt
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(d) an inductor
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25.
An ideal transformer has maximum efficiency when
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(a) copper losses are equal to
iron losses
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(b) copper losses are less than
iron losses
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(c) copper losses are more than
iron losses
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(d) copper losses and iron losses
are equal to windage losses
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26. For induction motors, normally
(a) the rotor winding is
connected to supply and the stator winding is short-circuited.
(b) the stator winding is connected to supply and the rotor winding is short-circuited. (c) both the stator and the rotor windings are connected to supply.
(d) the stator winding is
connected to supply and the rotor winding is open-circuited.
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27.
When load is removed, ……….......motor will run at the highest speed.
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(a) shunt
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(b) cumulative compound
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(c) differential compound
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(d) series
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28.
The colour of good Transformer oil is
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(a) Pale Yellow
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(b) Black
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(c) White
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(d) None
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29.
The capacity of a battery is expressed in terms of
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(a) current rating
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(b) voltage rating
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(c) ampere-hour rating
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(d) none of the above
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30. The main purpose of performing
open-circuit test on a transformer is to measure its
(a) Cu loss (b) core loss (c) total loss (d) insulation resistance. |
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31.
In a transformer, Wi = 15 KW and Wcu = 25 KW at full load. Total loss at
maximum efficiency will be
(a) 30 KW (b) 40 KW (c) 50 KW (d) 20 KW |
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33. Which of the following is not a
basic element of a transformer?
(a) core (b) primary winding (c) secondary winding (d) mutual flux. |
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34. As shown in the
figure, when R1 = R2 = R3 = R4 = R5 are low value resistors and the resistor
R3 becomes open circuited, the voltmeter will read
(a) Zero
(b) 50V (c) 125 V (d) 250 V |
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35.
H.R.C fuse is
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(a) a ceramic body having metal
end caps
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(b) a wire of platinum
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(c) a heavy cross-section of
copper or aluminium
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(d) a ceramic tube having carbon
rod inside it.
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ANSWER AS ASKED:
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36. If x + y = 3 and
y/x= 2 then y =?
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(a) 0
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(b) 1/2
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(c) 1
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(d) 3/2
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(e) 2
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37. BASIC : PASCAL : FORTRAN
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(a) CYCLOTRONE
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(b) COMPUTER
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(c) COBOL
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(d) BHOPAL
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38. If 2x-y=4 then
6x-3y=?
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(a) 15
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(b) 12
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(c) 18
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(d) 10
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39. Pick
the odd one out:
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(a) Curd
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(b) Butter
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(c) Oil
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(d) Cream
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40. Pick the odd one out:
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(a) Lake
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(b) Water
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(c) Pool
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(d) Pond
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41. Ohm : Watt : Volt
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(a) Light
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(b) Electricity
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(c) Hour
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(d) Ampere
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42. Pick the odd one out:
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(a) 36
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(b) 49
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(c) 56
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(d) 64
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43.
Pick the odd one out:
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(a) Square
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(b) Rectangle
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(c) Triangle
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(d)
Circle
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44.
A man invests Rs. 5,000 for three years at a certain rate of interest,
compounded annually. At the end of one year, it amounts to Rs. 5,600.
Calculate the rate of interest per annum.
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(a) 6%
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(b) 10%
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(c) 12%
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(d) 15%
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