MGVCL Exam Paper (30-07-2021 Shift 3)
A 1000 kVA ONAN cooled transformer has a load of 500 kVA throughout the day except for a period of 2 hours. What is the permissible overload for a duration of two hours. Assume the permissible load kVA as a fraction of rated kVA is 1.43.

700 kVA
1050 kVA
1430 kVA
715 kVA

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MGVCL Exam Paper (30-07-2021 Shift 3)
The DC offset in fault current causes conventional over-current (OC) relays to :

over-reach
sometimes under-reach and sometimes over-reach
reach remains unaffected due to DC offset
under-reach

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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 current flowing in to a balanced delta connected load through line 'a' is 10 A when the conductor of line ’b’ is open. With the current in line 'a' as reference, compute the symmetrical components of the line currents. Assume the phase sequence of ’abc’.

Ia₀ = 0 A.Ia₁ = (-1.66 + j2.88) A.Ia₂ = (1.66 + j2.88) A.
Ia₀ = 10 A.Ia₁ = (-1.66 + j2.88) A.Ia₂ = (1.66 + j2.88) A.
Ia₀ = 0 A.Ia₁ = (-5 + j2.88) A.Ia₂ = (5 - j2.88) A.
Ia₀ = 10 A.Ia₁ = (-5 + j2.44) A.Ia₂ = (5 - j2.44) A.

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