Which of the following single-phase motors has relatively poor starting torque ?
All single phase motors have zero starting torque
Repulsion motor
Universal motor
Capacitor motor
Capacitor motor
The wattage rating for a ceiling fan motor will be in the range
200 to 250 W
250 to 500 W
50 to 150 W
10 to 20 W
50 to 150 W
The speed of a universal motor is generally reduced by using
gear trains
chains
brakes
V-belts
gear trains
Which of the following motors can be used for unity power factor ?
Schrage motor
Shaded pole motor
Capacitor run motor
Hysteresis motor
Schrage motor
When a D.C. series motor is connected to A.C. supply the power factor will be low because of
none of the above
high inductance of field and armature circuits
induced current in rotor due to variations of flux
fine copper wire winding
high inductance of field and armature circuits
The direction of rotation of universal motor can be reversed the by reversing the flow of current through
either armature winding or field winding
armature winding
field winding
none of the above
either armature winding or field winding
Which type of load is offered by cranes and hoists ?
Reversing light start
Non-reversing no-load start
Gradually varying load
Reversing heavy start
Reversing heavy start
After the starting winding of a single phase induction motor is disconnected from supply it continues to run only on
rotor winding
field winding
running winding
compensating winding
running winding
Which of the following statements regarding repulsion-start induction motor is incorrect ?
In fractional horse power motors it has replaced the capacitor motors
It is not easily reversed
It makes quite a bit of noise on starting
It requires more maintenance of commutator and other mechanical devices
In fractional horse power motors it has replaced the capacitor motors
A.C. series motor as compared to D.C. series motor has
all of the above
less number of field turns
smaller brush width
more number of armature turns
all of the above
पोस्ट अच्छी लगी हो तो प्लीज नीचे दिए गए लिंक पर क्लिक कर शेयर जरुर करें
0 Comments