Electrical Online Test 26
Category –EE Online Test
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Attempt Free Electrical Online Test 26 Here. Read The Important Electrical MCQ From Below.
1) In a mercury arc rectifier positive ions are attracted towards
a. Mercury pool
b. Shell bottom
c. Cathode
d. anode.
Ans. b. Shell bottom
2) An unexcited single phase synchronous motor is
a. Reluctance motor
b. Repulsion motor
c. Universal motor
d. AC series motor.
Ans. a. Reluctance motor
3) The starting capacitor of a single phase motor is
a. Electrolytic capacitor
b. Ceramic capacitor
c. Paper capacitor
d. None of the above.
Ans. a. Electrolytic capacitor
4) 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. voltage and power factor both increase
5) A single phase motor generally used for small air compressor is
a. capacitor start capacitor run motor
b. reluctance motor
c. universal motor
d. Shaded pole motor.
Ans. a. capacitor start capacitor run motor
Electrical Online Test 26
6) The power factor of an alternator depends on
a. Load
b. Speed of rotor
c. Core losses
d. Armature losses.
Ans. a. Load
7) The starting torque of a capacitor start motor is
a. Zero
b. Low
c. Same as rated torque
d. More than rated torque.
Ans. b. Low
8) An ideal liquid insulating material should have low
a. Heat conductivity
b. Dielectric strength
c. Mechanical strength
d. Volatility.
Ans. d. Volatility.
9) Hysteresis loss varies with frequency (f) as
a. f
b. F 1.6
c. F 2
d. F 2.6
Ans. a. f
10) Synchronous motor can operate at
a. Lagging power factor only
b. Leading power factor only
c. Unity power factor only
d. Lagging, leading and unity power factor only
Ans. d. Lagging, leading and unity power factor only
Electrical Online Test 26
11) For a simplex lap winding, the winding pitch is equal to
a. + 2
b. – 2
c. ± 1
d. ± 2.
Ans. b. – 2
12) The fact that a conductor carries more current on the surface as compared to core, is known as
a. Skin effect
b. Corona
c. permeability
d. unsymmetrical fault.
Ans. a. Skin effect
13) Which of the following equipment needs direct current?
a. Relays
b. Telephones
c. Time switches
d. All of the above.
Ans. d. All of the above.
14) Which single phase ac motor will you select for record players and tape recorders ?
a. Hysteresis motor
b. Shaded pole motor
c. Reluctance motor
d. Two value capacitor motor.
Ans. a. Hysteresis motor
15) The function of protective relay in a circuit breaker is
a. To each any stray voltages
b. To open the contacts when the actuating quantity reaches a certain predetermined value
c. To limit arcing current during the operation of circuit breaker
d. To provide additional safety in the operation of circuit breaker.
Ans. b. To open the contacts when the actuating quantity reaches a certain predetermined value
Electrical Online Test 26
16) The frequency of voltage generated in an alternator depends on
a. number of poles
b. Rotating speed
c. Number of poles and rotating speed
d. Number of poles, rotating speed and type of winding.
Ans. c. Number of poles and rotating speed
17) 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. 9.9 kV
18) A capacitor start single phase induction motor is switched on the supply with its capacitor replaced by an inductor of equivalent reactance value. It will
a. Not start
b. Start and run
c. start and then stall
d. none of the above.
Ans. a. Not start
19) A circuit breaker is
a. Power factor correcting device
b. A device to neutralize the effect of transients
c. A waveform correcting device
d. a current interrupting device.
Ans. d. a current interrupting device.
20) Salient poles are generally used on Salient poles are generally used on
a. high speed prime movers only
b. medium speed prime movers only
c. low speed prime movers only
d. Low and medium speed prime movers.
Ans. d. Low and medium speed prime movers.
Electrical Online Test 26
21) Which of the following is not a type of the contactor for circuit breakers ?
a. Electro-magnetic
b. Electro-pneumatic
c. Pneumatic
d. Vacuum.
Ans. d. Vacuum.
22) For a simplex lap winding, the commutator pitch is equal to
a. +1
b. ± 1
c. -l
d. ± 2.
Ans. b. ± 1
23) SF6 gas
a. Is yellow in color
b. Has pungent odor
c. is highly toxic
d. Is non-inflammable.
Ans. d. Is non-inflammable.
24) In an alternator, voltage drops occurs in
a. Armature resistance only
b. Armature resistance and leakage reluctance
c. Armature resistance, leakage reluctance and armature reaction
d. Armature resistance, leakage reluctance, armature reaction and earth connections.
Ans. c. Armature resistance, leakage reluctance and armature reaction
25) 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. Single phase -4 wire.
Electrical Online Test 26
