Related Questions

Insertion of resistance in the rotcir of an induction motor to develop a given torque
A decreases the rotor current
B increases the rotor current
C rotor current becomes zero
D rotor current rernains same
A wound rotor induction motor is preferred, as compared to squirrel cage induction motor, when major consideration is
A Slop speed operation
B High starting torque
C Low windage losses
D All of the above
While starting a salient pole synchronous motor by induction motor action and connecting field discharge resistance across field, starting and accelerting torque is produced by
A induction motor torque in field winding
B induction motor torque in damper winding
C eddy current and hysteresis torque in pole faces
D reHetance motor torque due to saliency of the rotor
E all of the above methods
The maximum torque which a synchronous motor will develop at rest for any angular position of the rotor, at rated stator supply voltage and frequency, is known as
A locked-rotor torque
B synchronous torque
C pull up torque
D reluctance torque
The torque of a rotor in an induction motor under running condition is maximum
A At the unit value of slip
B At the zero value of slip
C At the value of the slip which makes rotor reactance per phase equal to the resistance per phase
D At the value of the slip which makes the rotor reactance half of the rotor
Insertion of resistance in the stator of an induction motor
A Increases the load torque
B Decreases the starting torque
C Increases the starting torque
D None of the above
The power input to an induction motor is 50 kW when it is running at 4% slip. If the stator resistance and core losses are neglected, the rotor copper loss is
A 30 kW
B 20 kW
C 2 kW
D 4 kW
In the squirrel-cage induction motor the rotor slots are usually given slight skew
A To reduce the magnetic hum and locking tendency of the rotor
B To increase the tensile strength of the rotor bars
C To ensure easy fabrication
D None of the above
In an induction motor the relationship between stator slots and rotor slots is that
A Stator slots are equal to rotor slots
B Stator slots are exact multiple of rotor slots
C Stator slots are not exact multiple of rotor slots
D None of the above
What will happen if the relative speed between the rotating flux of stator and rotor of the induction motor is zero?
A The slip of the motor will be 5%
B The rotor will not run
C The rotor will run at very high speed
D The torque produced will be very large

Next steps