Electrical Machines Objective Questions – Set 16

Synchronous condensers are used to

For a 3-phase, 4 pole, 50 Hz synchronous motor the frequency, pole number and the frequency are halved. The motor speed will be

Synchronising power of a synchronous motor varies

Which of the following statement is correct, if short circuit ratios is high

In a synchronous machine, if φ is the flux per pole and f is the frequency of the emf induced E then

Reactive power generated or delivered significantly depends on

Universal motors are used in

When excitation is increased (over excitation), the synchronous generator operates at

Two synchronous generators operating in parallel 200 MW and 400 MW respectively. The drooping characteristics of their governors are identical as 4% from no load to full load. Consider the governors operating at 50Hz on no load. What is the operating frequency, if the load is 600 MW?

In synchronous motor the torque is proportional to

In a synchronous generator with constant steam input supplies power to an infinite bus at a lagging power factor. If the excitation is increased

Which of the following motor has more stability

Stepper motor is used in

Two synchronous generators operating in parallel 200 MW and 400 MW respectively. The drooping characteristics of their governors are 4% and 5% from no load to full load. Consider the governors operating at 50Hz on no load. How will the machine share, if the load is 600 MW?

In a synchronous motor torque or load angle δ ------------- with increase in load

The synchronous reactance( Xs) is the

Stability of a synchronous motor ---------- with the increase in excitation.

Maximum power developed by a synchronous motor depends on

A 3 phase stepper motor has 6 stator poles and 4 rotor poles, then find the step angle?

In synchronous generator, inverted V curve is drawn between

In synchronous generator V curve is drawn between

Damper winding is used to

In a synchronous generator, if mechanical input is increased with constant excitation, the load angle will

Slip test is performed to determine

In which of the following motors DC excitation is not required?

The leakage reactance of a 3-phase alternator is determined by performing

Two synchronous generators operating in parallel 200 MW and 400 MW respectively. The drooping characteristics of their governors are identical as 4% from no load to full load. Consider the governors operating at 50Hz on no load. How will the machine share, if the load is 600 MW?

Synchronous reactance of an alternator represents

Number of slip rings in 3-phase synchronous motor will be

The results of a slip test for determining direct axis (X_d) and quadrature axis (X_q) reactances of a star connected salient pole alternator are given below Phase values: V_max = 108 V ; V_min = 96 V I_max = 12 A ; I_min = 10 A Hence the two reactances will be