A reluctance motor____________?
A. is self-starting
B. is constant speed motor
C. needs no D.C. excitation
D. all of the above
Single Phase Induction Motors
Which motor is normally free from mechanical and magnetic vibrations ?
Which motor is normally free from mechanical and magnetic vibrations ?
A. Split phase motor
B. Universal motor
C. Hysteresis motor
D. Shaded pole motor
As hysteresis motors are free from mechanical and magnetic vibrations therefore these are considered as suitable for__________?
As hysteresis motors are free from mechanical and magnetic vibrations therefore these are considered as suitable for__________?
A. fans
B. blowers
C. sound equipment
D. mixer grinders
The direction of rotation of universal motor can be reversed the by reversing the flow of current through__________?
The direction of rotation of universal motor can be reversed the by reversing the flow of current through__________?
A. armature winding
B. field winding
C. either armature winding or field winding
D. none of the above
When a D.C. series motor is connected to A.C. supply, the power factor will be low because of____________?
When a D.C. series motor is connected to A.C. supply, the power factor will be low because of____________?
A. high inductance of field and armature circuits
B. induced current in rotor due to variations of flux
C. fine copper wire winding
D. none of the above
In which single-phase motor, the rotor has no teeth or winding ?
In which single-phase motor, the rotor has no teeth or winding ?
A. Split phase motor
B. Reluctance motor
C. Hysteresis motor
D. Universal motor
The speed of a universal motor is generally reduced by using_________?
The speed of a universal motor is generally reduced by using_________?
A. gear trains
B. V-belts
C. brakes
D. chains
Which of the following single-phase motors has relatively poor starting torque ?
Which of the following single-phase motors has relatively poor starting torque ?
A. Universal motor
B. Repulsion motor
C. Capacitor motor
D. All single phase motors have zero starting torque
Which of the following motors can be used for unity power factor ?
Which of the following motors can be used for unity power factor ?
A. Capacitor run motor
B. Shaded pole motor
C. Hysteresis motor
D. Schrage motor
Which type of load is offered by cranes and hoists ?
Which type of load is offered by cranes and hoists ?
A. Gradually varying load
B. Non-reversing, no-load start
C. Reversing, light start
D. Reversing, heavy start