Electrical Engg (EEE) - MCQ Practice Questions

In a 3-phase transformer with Delta-Star connection, the secondary voltage phase angle leads the primary by:

What is the relationship between electrical and mechanical power in a DC motor running at steady state?

In a synchronous motor, the angle between stator MMF and rotor MMF at full load is:

In a DC generator, armature reaction causes the neutral plane to:

A 3-phase induction motor draws 50 A at 0.7 lagging power factor when running at full load. What is the reactive power?

The primary advantage of a brushless DC motor (BLDC) over conventional DC motor is:

In a transformer under short-circuit test, the secondary is short-circuited and primary voltage is reduced to make rated current flow. The measured power is the:

Which of the following statements about a DC shunt motor is true?

The efficiency of a squirrel-cage induction motor improves with increasing load mainly because:

A DC motor is running at 1500 rpm with an armature current of 20 A. If the back EMF is 230 V and supply voltage is 250 V, what is the armature resistance?

A series DC motor is suitable for which of the following applications?

The open-circuit test on a transformer primarily helps to determine:

In a permanent magnet synchronous motor (PMSM), the torque is primarily developed due to:

In a wound-rotor induction motor, adding external resistance to the rotor circuit:

The commutation in a DC machine is said to be 'overcommutated' when:

In an induction motor, the torque under running conditions is proportional to:

Which of the following represents the condition for maximum power transfer in a DC generator connected to external load?

In a 3-phase transformer with Y-Δ connection, the secondary voltage lags the primary by:

For a DC shunt motor operating at rated conditions, if the load is suddenly increased, the motor will:

A DC series motor is used in electric trains. If the load torque decreases suddenly, what happens to the motor speed?