Electrical Machines and Applications — Winter 2024

Explain the significance of interpole and compensating windings in DC Machine.

Derive emf equation of 1-ϕ transformer.

Explain the theory of production of rotating magnetic field with 3-ϕ supply in induction motor.

Explain open-circuit test of 1-ϕ transformer.

List the conditions for parallel operation of 3-ϕ transformers.

Explain Scott connection of transformers with necessary diagrams.

Explain auto-transformer. Derive the equation for the saving in copper. List the applications of auto-transformer.

Explain about the power stages in induction motor.

Derive the condition for maximum torque under running condition for induction motor. Also, derive the equation for maximum torque.

Explain double field revolving theory of 1-ϕ induction motor.

Define slip. Derive the equation of speed of rotor field in space.

Explain auto-transformer starter for 3-ϕ induction motor.

Draw and explain the equivalent circuit for 1- ϕ induction motor.

Compare Lap Winding and Wave Winding.

Derive the equation of armature torque for DC motor.

Explain the necessity of starter in DC Motor. Discuss four-point starter with necessary diagram.

Explain power flow diagram of DC Motor.

Derive the EMF equation of DC generator for lap winding.

Describe the theory of armature reaction in DC generator with necessary diagram.

Define Distribution factor, Coil-span factor and voltage regulation.

Explain the working of AC servomotor with necessary diagram.

Explain the effect of increased load on synchronous motor with constant excitation with the help of vector diagram.

Define pole pitch, coil pitch and commutator pitch.

Explain the working of DC servomotor with necessary diagram.

Explain MMF method for finding voltage regulation of an alternator.