Electrical Machines and Applications — Summer 2025

Define Transformer. Explain working principle of transformer.

Explain torque-slip characteristics of three-phase induction motor.

Explain three-point starter for DC shunt motor with neat diagram.

Discuss pitch factor and distribution factor of an alternator.

List and explain the conditions for parallel operation of single-phase transformer.

Explain construction and working of BLDC motor with necessary diagram.

Explain construction and working of stepper motor with necessary diagram.

Explain the effect of change in supply voltage on torque and speed of three-phase induction motor.

Explain DOL starter of three-phase induction motor with neat sketch.

Explain the theory of production of rotating magnetic field with three-phase supply in three-phase induction motor.

Derive the expression of starting torque for three-phase induction motor.

Explain the methods of speed control for three-phase induction motor.

Explain the double field revolving theory for single-phase induction motor.

Explain short circuit test on single-phase transformer.

Derive the emf equation of DC generator.

Explain Scott connection for three-phase transformer with neat diagram.

Derive the emf equation of single-phase transformer.

Explain losses in DC machines.

Draw the vector diagram of single-phase transformer considering the effect of winding resistance and reactance for R, Land Cload.

Explain the speed-torque characteristics of DC shunt motor.

Derive the expression of armature torque for DC motor.

Explain synchronous impedance method for voltage regulation of an alternator.

Explain function of yoke, pole core and pole shoe in DC generator.

Explain rheostatic control method for speed control of DC motor.

Explain zero power factor method for voltage regulation of an alternator.