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.

increases by 30%
remains unaltered
increases marginally
decreases marginally

ANSWER DOWNLOAD EXAMIANS APP

MGVCL Exam Paper (30-07-2021 Shift 1)
Consider the following two statements and choose the correct answer.
Statement 1: The V-curves of a synchronous motor show relationship between armature current and supply voltage.
Statement 2: The plot of power factor against the field current of synchronous motor is known as inverted V curves.

Both Statement 1 and Statement 2 are FALSE
Statement 1 is TRUE and Statement 2 is FALSE
Both Statement 1 and Statement 2 are TRUE
Statement 1 is FALSE and Statement 2 is TRUE

ANSWER EXPLANATION DOWNLOAD EXAMIANS APP

MGVCL Exam Paper (30-07-2021 Shift 1)
Consider the following statements and choose the correct option:
Statement 1: The magnitude of earth fault current for a given fault position within a winding depends upon the method of neutral grounding.
Statement 2: Earth fault protection for an electric motor is provided by means of instantaneous overcurrent relay.

Statement 1 is TRUE and Statement 2 is FALSE
Statement 1 is FALSE and Statement 2 is TRUE
Both Statement 1 and Statement 2 are FALSE
Both Statement 1 and Statement 2 are TRUE

ANSWER EXPLANATION DOWNLOAD EXAMIANS APP

MGVCL Exam Paper (30-07-2021 Shift 1)
Case 1: The PV connected to the DC bus was injecting 20 kW of power constituting of 1 kW of loss
Case 2: The same PV is connected to the AC bus constituting to 1.5 kW loss. Find out the change in efficiency from Case 1 to Case 2?

5% decrease
2.5% increase
2.5% decrease
5% increase

ANSWER EXPLANATION DOWNLOAD EXAMIANS APP

MGVCL Exam Paper (30-07-2021 Shift 1)
As per ___ guidelines, if the ratio of carbon dioxide (CO₂) and carbon monoxide (CO) in dissolved gas analysis is ___, it is predicted that the condition of paper insulation inside the transformer is poor.

IEC-599, less than 11
IEC-599, more than 11
IEC-899, less than 11
IEC-899, more than 11

ANSWER EXPLANATION DOWNLOAD EXAMIANS APP
MORE MCQ ON MGVCL Exam Paper (30-07-2021 Shift 1)