Single phase induction motors

31. In a capacitor start single-phase motor, when capacitor is replaced by a resistance

torque will increase
the motor will consume less power
motor will run in reverse direction
motor will continue to run in same direction

Detailed SolutionIn a capacitor start single-phase motor, when capacitor is replaced by a resistance

32. In a shaded pole single-phase motor, the revolving field is produced by the use of

inductor
capacitor
resistor
shading coils

Detailed SolutionIn a shaded pole single-phase motor, the revolving field is produced by the use of

33. The electric motor used in portable drills is

capacitor run motor
hysteresis motor
universal motor
repulsion motor

Detailed SolutionThe electric motor used in portable drills is

34. Which of the following motors is used in tape-recorders ?

Hysteresis motor
Reluctance motor
Capacitor-run motor
Universal motor

Detailed SolutionWhich of the following motors is used in tape-recorders ?

35. For which of the applications a reluctance motor is preferred ?

Electric shavers
Refrigerators
Signalling and timing devices
Lifts and hoists

Detailed SolutionFor which of the applications a reluctance motor is preferred ?

36. In a universal motor, the most common cause of brush sparking is

open armature winding
shorted armature winding
shorted field winding?
high commutator mica E. all of the above

Detailed SolutionIn a universal motor, the most common cause of brush sparking is

37. If the centrifugal switch of a two-value capacitor motor using two capacitors fails to open then

motor will not come up to speed
motor will not carry the load
current drawn by the motor will be excessively high
electrolytic capacitor will, in all probability, suffer break down

Detailed SolutionIf the centrifugal switch of a two-value capacitor motor using two capacitors fails to open then

38. To reverse the direction of rotation of acapacitor start motor while it is running we should

disconnect motor from the supply till it stops then reconnect it to supply with reversed connection of main or auxiliary winding
disconnect motor from supply and immediately reconnect it to supply with reversed con-nections of the main winding
reverse the direction of connection of the auxiliary winding and after motor comes to rest then connect auxiliary winding to the supply
reverse the direction of connections of the auxiliary winding and immediately connect it to supply

Detailed SolutionTo reverse the direction of rotation of acapacitor start motor while it is running we should

39. The power factor of a single-phase induction motor is usually

lagging
always leading
unity
unity to 0.8 leading

Detailed SolutionThe power factor of a single-phase induction motor is usually

40. Which of the following single-phase induction motors is generally used in time phonographs?

Resistance start
Capacitor start capacitor run
Shaded pole
Universal

Detailed SolutionWhich of the following single-phase induction motors is generally used in time phonographs?

Page 1Page 2Page 3Page 4Page 5
Test 1Test 2