1. By pushing and pulling the rotor shaft of a motor, we can check its ?

end play

side play

firmness of mounting

free shaft movement

Answer: end play

Explanation:


2. When a D.C. series motor is connected to AC. supply, the power factor will be low because of ?

high inductance of field and armature circuits

induced current in rotor due to variations of flux

fine copper wire winding

none of the above

Answer: high inductance of field and armature circuits

Explanation:


3. ln case of high speed universal motor which of the following needs more attention ?

End play

Air gap

Insulation in rotor

Balancing of rotor

Answer: Balancing of rotor

Explanation:


4. In A.C. series motor compensating winding is employed to ?

reduce the effects of armature reaction

increase the torque

reduce sparking at the brushes

none of the above

Answer: reduce sparking at the brushes

Explanation:


5. The range of efficiency for shaded pole motors is ?

50% to 75%

80% to 90%

50% to 75%

5% to 35%

Answer: 5% to 35%

Explanation:


6. In repulsion motor direction of rotation of motor ?

is opposite to that of brush shift

is the same as that of brush shift

is independent of brush shift

all of the above

Answer: is the same as that of brush shift

Explanation:


7. In a two value capacitor motor, the capacitor used for running purposes is ?

air capacitor

paper spaced oil-filled type

ceramic type

a..c. electrolytic type

Answer: paper spaced oil-filled type

Explanation:


8. In which single-phase motor, the rotor has no teeth or winding ?

Split phase motor

Reluctance motor

Hysteresis motor

Universal motor

Answer: Hysteresis motor

Explanation:


9. The motor used for the compressors is ?

DC series motor

shaded pole motor

Capacitor-start capacitor-run motor

reluctance motor

Answer: Capacitor-start capacitor-run motor

Explanation:


10. Which of the following motors is used in a situation where load increases with speed ?

Induction motor

3 phase series motor

Schrage motor

Hysteresis motor

Answer: 3 phase series motor

Explanation: