Polyphase Induction Motors MCQ Questions & Answers | Electrical Engineering

A. 730 r.p.m.

B. 960 r.p.m.

C. 1440 r.p.m.

D. 2880 r.p.m.

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

A. Resistance rise method

B. Thermometer method

C. Embedded temperature method

D. All above methods

A. Inversely proportional to $$\left( {\sqrt {{\text{slip}}} } \right)$$

B. Directly proportional to $${\left( {{\text{slip}}} \right)^2}$$

C. Inversely proportional to slip

D. Directly proportional to slip

A. Self-starting with zero torque

B. Self-starting with high torque

C. Self-starting with low torque

D. Non-self starting

A. Directly proportional to slip

B. Inversely proportional to slip

C. Proportional to the square of the slip

D. None of the above

A. High loads

B. Low voltage supply

C. Improper design of machine

D. Harmonics developed in the motor

A. Low voltage supply

B. High loads

C. Harmonics developed in the motor

D. Improper design of the machine

A. The magnetizing current of the rotor will decrease

B. The power factor will decrease

C. Speed of motor will increase

D. The windage losses will increase

A. Slip ring type

B. Squirrel-cage type

C. Any of the above

D. None of the above