Electrical Engg (EEE) - MCQ Practice Questions

Which of the following is the primary function of a commutator in a DC machine?

The back EMF in a DC motor is given by the expression?

In a three-phase induction motor, the rotating magnetic field is produced by:

The synchronous speed of a 4-pole, 50 Hz induction motor is:

The slip of an induction motor is defined as:

A DC shunt motor is running at no load. If the field winding is suddenly short-circuited, the motor will:

In a transformer, the turns ratio k = N2/N1. If k > 1, the transformer is:

The efficiency of a transformer is maximum when:

The starting current of a 3-phase induction motor is typically how many times the full-load current?

Which method is NOT used for starting a three-phase induction motor?

A DC series motor is suitable for:

The power factor of an induction motor at full load is typically:

What is the relationship between slip and rotor frequency in an induction motor?

In a synchronous motor, the damper winding is used to:

A 100 kVA transformer has 1000 primary turns and 100 secondary turns. The turns ratio and voltage ratio are:

The torque developed in a 3-phase induction motor is maximum at a slip of:

An 8-pole induction motor running at 720 rpm with 50 Hz supply has a slip of approximately:

In a DC machine, armature reaction causes:

The equivalent circuit of an induction motor includes a series resistance R2/s in the rotor branch. The power dissipated in this resistance represents:

A 3-phase induction motor has 4 poles and is connected to a 50 Hz supply. What is the synchronous speed?