MGVCL Exam Paper (30-07-2021 Shift 3)
Two-wattmeter method is used to measure the power taken by a 3-phase induction motor on no load. The wattmeter readings are 400 W and -50 W. Calculate the reactive power taken by the load

350√3 VAR
350/√3 VAR
450√3 VAR
450/√3 VAR

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MGVCL Exam Paper (30-07-2021 Shift 3)
A 50 Hz synchronous generator is connected to an infinite bus through a line. The p.u. reactances of generator and the line are j0.4 p.u. and j0.2 p.u. respectively. The generator no load voltage is 1.1 p.u. and that of infinite bus is 1.0 p.u. The inertia constant of the generator is 4 MW-sec/MVA. Determine the frequency of natural oscillations if the generator is loaded to 60% of its maximum power transfer capacity and small perturbation in power is given.

1.2 Hz
1.6 Hz
0.8 Hz
1.8 Hz

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MGVCL Exam Paper (30-07-2021 Shift 3)
In a 3-phase, 4-wire, 400/230 V system, a lamp (L₁) of 100 W is connected to one phase and neutral and a lamp (L₂) of 150 W is connected to the second pahse and neutral. If the neutral wire is disconnected accidently, what will be the voltage across a 150 W lamp (L₂)?

180 V
120 v
160 V
240 V

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MGVCL Exam Paper (30-07-2021 Shift 3)
The most commonly used method for the protection of three phase feeder is

None of these
Time graded protection
Reverse power protection
Differential protection

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