Electrical Machines and Applications — Winter 2022

Explain the basic principle of operation of synchronous motor.

Derive EMF equation of single-phase transformer.

Explain double-field revolving theory of single-phase induction motor with necessary diagrams.

Discuss function of yoke, pole core & pole shoes and commutator in DC generator.

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

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

Explain characteristics of separately excited DC generator.

Explain characteristics of DC series motor.

Derive EMF equation of DC generator.

Explain open circuit and short circuit test of single-phase transformer with necessary diagrams.

Explain the phenomena of armature reaction in DC generator.

Derive the equation of armature torque for DC motor.

Discuss the Scott connection of transformers.

Draw the vector diagram of single-phase transformer with R, Land Cload considering effect of armature resistance but no magnetic leakage.

Prove that the core losses in the transformer remains constant under all load conditions.

Define voltage regulation of an alternator. Explain the Rothert’s MMF method for determining voltage regulation of an alternator.

Explain working of auto-transformer with necessary diagram.

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

Define voltage regulation of an alternator. Explain the ZPF method for determining voltage regulation of an alternator.

List advantages and disadvantages of polyphase induction motor.

Derive equation for starting torque of three-phase induction motor.

Write technical note on: Stepper motor.

Explain DOL starter of three-phase induction motor.

Determine the condition of maximum torque under running conditions for three- phase induction motor.

Write technical note on: Linear Induction Motor.