MGVCL Exam Paper (30-07-2021 Shift 1)
A transformer designed for operation at 60 Hz supply is working at 50 Hz supply system without changing its voltage and current ratings. Compared to the full load efficiency at 60 Hz, the full load transformer efficiency at 50 Hz.

decreases marginally
remains unaltered
increases marginally
increases by 30%

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MGVCL Exam Paper (30-07-2021 Shift 1)
Insulation Power Factor testing on an oil-filled transformer is not helpful in determining ___

Condition of paper insulation (change in watts losses)
Whether the oil test indicates moisture
Movement of the windings (change in capacitance)
Turns ratio values

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MGVCL Exam Paper (30-07-2021 Shift 1)
___ is the rms value of the total current comprising the AC and DC components of the current in the circuit breaker pole at the instant of contact separation.

Symmetrical short circuit current
Symmetrical breaking current
Making current
Asymmetrical breaking current

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MGVCL Exam Paper (30-07-2021 Shift 1)
A THHN conductor will have 75°C termination on one end and a 60/75°C termination on the other, which ampacity column will be used?

None of these
60°C column
90°C column
75°C column

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