AC THREE PHASE MOTOR - Quiz

1) What is the purpose of using thermal cutout in addition to fuse in A.C motor circuit?

Protect from heavy load Protect against high voltage Allow for continuous over loading Protect against dead short circuit

2) Which type of motor is used to provide high starting torque at variable speed?

Universal motor Permanent capacitor motor 3 Phase slip ring induction motor 3 Phase single squirrel cage induction motor

3) What is the relation between torque and slip in an A.C induction motor?

Slip increases torque decreases Slip increases torque increases Slip decreases torque increases Slip decreases torque decreases

4) What is effect of A.C induction motor if rotor bar is in open circuit?

Vibration of shaft Motor will not start Runs in slow speed Over heating of motor

5) Which type of wire is used for rewinding of A.C 3 phase motors?

Super enamelled copper wire PVC covered copper winding wire Single cotton covered copper wire Double cotton covered copper wire