Practice Test: Question Set - 04
1. Insertion of reactance in the rotor circuit
- (A) Reduces starting torque as well as maximum
torque
- (B) Increases starting torque as well as maximum
torque
- (C) Increases starting torque but maximum torque
remains unchanged
- (D) Increases starting torque but maximum torque
decreases
2. Slip ring motor is preferred over squirrel cage induction motor where
- (A) High starting torque is required
- (B) Load torque is heavy
- (C) Heavy pull out torque is required
- (D) All of the above
3. In squirrel cage induction motors, the rotor slots are usually given slight skew in order to
- (A) Reduce windage losses
- (B) Reduce eddy currents
- (C) Reduce accumulation of dirt and dust
- (D) Reduce magnetic hum
4. The good power factor of an induction motor can be achieved if the average flux density in the air gap is
- (A) Absent
- (B) Small
- (C) Large
- (D) Infinity
5. For which motor the speed can be controlled from rotor side?
- (A) Squirrel-cage induction motor
- (B) Slip-ring induction motor
- (C) Both (A) and (B)
- (D) None of the above
6. Size of a high speed motor as compared to low speed motor for the same H.P. will be
- (A) Bigger
- (B) Smaller
- (C) Same
- (D) Any of the above
7. The speed characteristics of an induction motor closely resemble the speed-load characteristics of which of the following machines
- (A) D.C. series motor
- (B) D.C. shunt motor
- (C) Universal motor
- (D) None of the above
8. The vafcie of transformation ratio of an induction motor can be found by
- (A) Open-circuit test only
- (B) Short-circuit test only
- (C) Stator resistance test
- (D) None of the above
9. The circle diagram for an induction motor cannot be used to determine
- (A) Efficiency
- (B) Power factor
- (C) Frequency
- (D) Output
10. Temperature of the stator winding of a three phase induction motor is obtained by
- (A) Resistance rise method
- (B) Thermometer method
- (C) Embedded temperature method
- (D) All above methods
Blogger Comment
Facebook Comment