G.K. Practice Test: Question Set - 04
1. If A.C is fed by mistake to a D.C motor, then the D.C motor will
- (A) Burn
as the eddy currents in the field produces heat
- (B) Run
at its normal speed
- (C) Run
at a lower speed
- (D) Run
continuously, but the sparking takes place at the brushes
2. The following motor is preferred for locomotives motor drives
- (A) A.C Series
motor
- (B) Induction
motor
- (C) D.C Series
motor
- (D) Synchronous
motor
3. Which of the following motors has high starting torque?
- (A) D.C
shunt motor
- (B) Squirrel
cage induction motor
- (C) D.C Series
motor
- (D) A.C Series
motor
4. In a D.C generator, following loss will be minimum
- (A) Copper loss
- (B) Iron loss
- (C) Friction
loss
- (D) Shunt field
copper loss
5. If the excitation to the field of the D.C motor is constant, then the torque developed in the motor is proportional to
- (A) Armature
current
- (B) Field
current
- (C) Speed
- (D) Magnetic
flux
6. Eddy current loss in a D.C shunt generator is proportional to
- (A) Flux density
- (B) √(Flux
density)
- (C) 1/ Flux
density
- (D) (Flux
density)²
7. The torque of a D.C series motor with increase in speed
- (A) Increases
gradually
- (B) Decreases
linearly
- (C) Remain
constant
- (D) First
decreases rapidly and then slowly
8. The function of the commutator in a D.C machine is
- (A) To
change alternating current to a direct current
- (B) To
improve commutation
- (C) To
improve efficiency of motor
- (D) To
change alternating voltage to direct voltage
9. The torque in induction motor is proportional to
- (A) Slip s
- (B) 1/s
- (C) s²
- (D) 1 - s
10. Which of the following motors is usually used in household refrigerator?
- (A) D.C shunt
motor
- (B) Reluctance
motor
- (C) Single phase
induction motor (split phase start or induction run motor)
- (D) Synchronous
motor
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