Electrical Machines Objective Questions
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Which of the following statement is correct, if short circuit ratios is high
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The leakage reactance of a 3phase alternator is determined by performing
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In a synchronous motor torque or load angle δ  with increase in load
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In which of the following motors DC excitation is not required?
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Synchronising power of a synchronous motor varies
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Slip test is performed to determine
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Stability of a synchronous motor  with the increase in excitation.
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Reactive power generated or delivered significantly depends on
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In synchronous motor the torque is proportional to
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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?
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In synchronous generator V curve is drawn between
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In a synchronous generator, if mechanical input is increased with constant excitation, the load angle will
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Universal motors are used in
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In a synchronous generator with constant steam input supplies power to an infinite bus at a lagging power factor. If the excitation is increased
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Which of the following motor has more stability
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The synchronous reactance( Xs) is the
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When excitation is increased (over excitation), the synchronous generator operates at
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In synchronous generator, inverted V curve is drawn between
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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?
Correct!
Wrong!

In a synchronous machine, if φ is the flux per pole and f is the frequency of the emf induced E then
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Maximum power developed by a synchronous motor depends on
Correct!
Wrong!

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?
Correct!
Wrong!

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

Synchronous condensers are used to
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A 3 phase stepper motor has 6 stator poles and 4 rotor poles, then find the step angle?
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Synchronous reactance of an alternator represents
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Damper winding is used to
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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
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Stepper motor is used in
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Number of slip rings in 3phase synchronous motor will be
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