Electrical Engg (EEE) - MCQ Practice Questions

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:

In a synchronous motor, the pull-out torque depends on:

A transformer is operating at 110% of rated voltage. The core loss will be approximately:

The efficiency of a DC generator is maximum when:

A 100 kW, 3-phase induction motor has a full-load slip of 0.04. The rotor copper loss at full load is:

The reluctance torque in a synchronous motor is maximum when the load angle is:

Which statement is correct regarding the torque-slip characteristic of a squirrel-cage induction motor?

A 3-phase, 50 Hz, 4-pole synchronous motor operates at rated speed. The excitation is reduced by 20%. What happens?

In a synchronous generator connected to an infinite bus, if the excitation is increased beyond rated value:

In a synchronous generator, the voltage regulation is negative when:

For a 3-phase synchronous motor connected to infinite bus, increasing field excitation beyond the critical value will:

The cogging torque in a DC motor is primarily due to:

A 3-phase induction motor develops maximum torque at a slip of 0.4. The motor is operating at slip 0.1. What is the ratio of starting torque to running torque?

A synchronous generator operating at leading power factor supplies current to an infinite bus. This condition represents:

The crawling phenomenon in induction motors occurs due to:

A synchronous motor is running at no-load with normal excitation. If excitation is increased, the armature current will:

The phenomenon of cogging in induction motors occurs due to: