Electrical Machines Objective Questions
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Slip test is performed to determine
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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. How will the machine share, if the load is 600 MW?
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In which of the following motors DC excitation is not required?
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Reactive power generated or delivered significantly depends on
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In synchronous generator V curve is drawn between
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Maximum power developed by a synchronous motor depends on
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In synchronous generator, inverted V curve is drawn between
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The leakage reactance of a 3phase alternator is determined by performing
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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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The synchronous reactance( Xs) is the
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Which of the following motor has more stability
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Synchronising power of a synchronous motor varies
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In a synchronous motor torque or load angle δ  with increase in load
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Universal motors are used in
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In a synchronous generator, if mechanical input is increased with constant excitation, the load angle will
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When excitation is increased (over excitation), the synchronous generator operates at
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Stability of a synchronous motor  with the increase in excitation.
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In synchronous motor the torque is proportional to
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Number of slip rings in 3phase synchronous motor will be
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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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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?
Correct!
Wrong!

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?
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Wrong!

A 3 phase stepper motor has 6 stator poles and 4 rotor poles, then find the step angle?
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Synchronous condensers are used to
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Synchronous reactance of an alternator represents
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Which of the following statement is correct, if short circuit ratios is high
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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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Damper winding is used to
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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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Stepper motor is used in
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