A. resistance rise method
B. thermometer method
C. embedded temperature method
D. all above methods
A. slip ring type
B. squirrel cage type
C. any of the above
D. none of the above
For driving high inertia loads best type of induction motor suggested is_____________? Read More »
Polyphase Induction Motors A. decreases the rotor current
B. increases the rotor current
C. rotor current becomes zero
D. rotor current rernains same
Insertion of resistance in the rotor of an induction motor to develop a given torque? Read More »
Polyphase Induction Motors A. reduces starting torque as well as maximum torque
B. increases starting torque as well as maximum torque
C. increases starting torque but maxi-mum torque remains unchanged
D. increases starting torque but maxi-mum torque decreases
Insertion of reactance in the rotor circuit_______? Read More »
Polyphase Induction Motors A. it is run on load
B. it is run in reverse direction
C. it is run on voltage higher than the rated voltage
D. e.m.f. is injected in the rotor circuit
An induction motor can run at synchronous speed when____________? Read More »
Polyphase Induction Motors A. rotor leakage reactance
B. stator reactance
C. the reactive lagging magnetizing current necessary to generate the magnetic flux
D. all of the above
The low power factor of induction motor is due to___________? Read More »
Polyphase Induction Motors A. supply frequency
B. supply voltage
C. copper losses in motor
D. none of the above
In induction motor, percentage slip depends on__________? Read More »
Polyphase Induction Motors A. sR2X2 = 1
B. sR2 = X2
C. R2 = sX2
D. R2 = s2X2
A. high inductance arid low resistance
B. low inductance and high resistance
C. low inductance and low resistance
D. high inductance and high resistance
In case of a double cage induction motor, the inner cage has__________? Read More »
Polyphase Induction Motors A. the power factor will be low
B. windage losses will be more
C. bearing friction will reduce
D. copper loss will reduce In an induction motor
In an induction motor if air-gap is increased__________? Read More »
Polyphase Induction Motors