A. to short circuit the rotor at slip rings
B. to short circuit the starting resistances in the starter
C. to short circuit the stator phase of motor to form star
D. none of the above
Related Mcqs:
- Short-circuit test on an induction motor cannot be used to determine___________?
A. windage losses
B. copper losses
C. transformation ratio
D. power scale of circle diagram - When the equivalent circuit diagram of doouble squirrel-cage induction motor is constructed the two cages can be considered__________?
A. in series
B. in parallel
C. in series-parallel
D. in parallel with stator - If a 3-phase supply is given to the stator and rotor is short circuited rotor will move___________?
A. in the opposite direction as the direction of the rotating field
B. in the same direction as the direction of the field
C. in any direction depending upon phase squence of supply - The torque of an induction motor is___________?
A. directly proportional to slip
B. inversely proportional to slip
C. proportional to the square of the slip
D. none of the above - The starting torque of a squirrel-cage induction motor is___________?
A. low
B. negligible
C. same as full-load torque
D. slightly more than full-load torque - The good power factor of an induction motor can be achieved if the average flux density in the air gap is___________?
A. absent
B. small
C. large
D. infinity - In case of the induction motors the torque is___________?
A. inversely proportional to (Vslip)
B. directly proportional to (slip)2
C. inversely proportional to slip
D. directly proportional to slip - The torque developed in the cage induction motor with autostarter is___________?
A. k/torque with direct switching
B. K x torque with direct switching
C. K2 x torque with direct switching
D. k2/torque with direct switching - In a squirrel cage motor the induced e.m.f. is___________?
A. dependent on the shaft loading
B. dependent on the number of slots
C. slip times the stand still e.m.f. induced in the rotor
D. none of the above - A 3-phase induction motor delta connected is carrying too heavy load and one of its fuses blows out. Then the motor______________?
A. will continue running burning its one phase
B. will continue running burning its two phase
C. will stop and carry heavy current causing permanent damage to its winding
D. will continue running without any harm to the winding
