Load test on Single Phase Induction Motor Viva Questions - Set 07 - ObjectiveBooks

# Practice Test: Question Set - 07

1. To reverse the direction of rotation of a capacitor start motor while it is running we should
(A) Disconnect motor from the supply till it stops then reconnect it to supply with reversed connection of main or auxiliary winding
(B) Disconnect motor from supply and immediately reconnect it to supply with reversed connections of the main winding
(C) Reverse the direction of connection of the auxiliary winding and after motor comes to rest then connect auxiliary winding to the supply
(D) Reverse the direction of connections of the auxiliary winding and immediately connect it to supply

2. Locked rotor current of a shaded pole motor is
(A) Equal to full load current
(B) Less than full load current
(C) Slightly more than full load current
(D) Several times the full load current

3. In a capacitor start motor, the phase displacement between starting and running winding can be nearly
(A) 10°
(B) 30°
(C) 60°
(D) 90°

4. Which of the following motors is used in mixes?
(A) Repulsion motor
(B) Reluctance motor
(C) Hysteresis motor
(D) Universal motor

5. A single-phase induction motor is
(A) Inherently self-starting with high torque
(B) Inherently self-starting with low torque
(C) Inherently non-self-starting with low torque
(D) Inherently non-self-starting with high torque

6. The wattage of motor for driving domestic sewing machine will be around
(A) 100 to 150 W
(B) 40 to 75 W
(C) 10 to 30 W
(D) 5 to 10 W

7. A reluctance motor
(A) Is self-starting
(B) Is constant speed motor
(C) Needs no D.C. excitation
(D) All of the above

8. The shaded pole motor is used for
(A) High starting torque
(B) Low starting torque
(C) Medium starting torque
(D) Very high starting torque

9. If a single phase induction motor runs slower than normal, the most likely defect is
(A) Worn bearings
(B) Short-circuit in the winding
(C) Open-circuit in the winding
(D) None of the above

10. A.C. series motor as compared to D.C. series motor has
(A) Smaller brush width
(B) Less number of field turns
(C) More number of armature turns
(D) All of the above

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