Electrical Engineering MCQ with Answers

Question No.1. A d.c. shunt motor runs at no load speed of 1140 r.p.m. At full load, armature reaction
weakens the main flux by 5% whereas the armature circuit voltage drops by 10%. The motor full load speed in r.p.m. is
(A) 1200
(B) 1203
(C) 1000
(D) 1080
Answer: (D) 1080
Question No.2 The voltage at the two ends of a transmission line are 132 KV and its reactance is
40 ohm. The Capacity of the line is
(A) 251.5 MW
(B) 217.8 MW
(C) 435.6 MW
(D) 500 MW
Answer: (C) 435.6 MW

Question No.3. The gravity controlled instrument has crowded scale because current is proportional to
(A) balancing weight
(B) deflection angle
(C) sine of deflection angle
(D) Location of CT
Ans: (C) sine of deflection angle

Question No.4. For LV applications (below 1 kV), ______________ cables are used.
(A) Paper insulated.
(B) Single core cables.
(D) Oil filled.
Answer: B) Single core cables.

Question No.5. The eddy current loss in an a-c electric motor is 100 watts at 50 Hz. Its loss at 100
Hz will be
(A) 25 watts
(B) 400 watts
(C) 200 watts
D) 219 watts
Answer: (B) 400 watts

Question No.6. The rotor frequency for a 3 phase 1000 RPM 6 pole induction motor with a slip of
0.04 is________Hz
(A) 8
(B) 4
(D) 2
Answer: (D) 2

Question No.7. In case of a universal motor, torque pulsation is minimized by _________.
(A) load inertia
(B) rotor inertia
(C) both rotor and load inertia
(D) none of the above
 Answer: (C) both rotor and load inertia

Question No.8. The pressure coil of a wattmeter should be connected on the supply side of the current coil
(A) supply voltage is low
(B) load impedance is low
(C) load impedance is high
(D) none of the above
Answer: (C) load impedance is high

Question No.9. The boundary of the protective zone is determined by the
(A) Location of CT
(B) sensitivity of relay used
(C) Location of PT
(D) None of these
Answer: (B) sensitivity of relay used

Question No.10. The two windings of a transformer is
(A) conductively linked.
(B) electrically linked.
(C) not linked at all.
(D) inductively linked.
 Answer :(D) inductively linked.

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