DGVCL EXAM PAPER (11-12-2011) QUIZ

All the peripheral devices connected to a computer require power to work. Which of the following voltages is required for the motherboard to work?

Positive cycle of sine wave

AC

Negative cycle of sine wave

DC

TRUE ANSWER : ?
YOUR ANSWER : ?

The purpose of providing a choke in a tube light is

To eliminate corona effect

To limit the current to an appropriate value

To avoid radio interference

To improve the power factor

TRUE ANSWER : ?
YOUR ANSWER : ?

In a series RLC circuit at resonance

Current is minimum and power factor is unity

Current is maximum and power factor is unity

Current is maximum and power factor is 0.5

Current is minimum and power factor is 0.5

TRUE ANSWER : ?
YOUR ANSWER : ?

In carrier current protection, the purpose of the wave trap is for

Trapping power frequency waves

Trapping high frequency waves entering into generator/transformer unit.

All of these

Tripping fault current

TRUE ANSWER : ?
YOUR ANSWER : ?

The efficiency of a transformer at full load, 0.8 p.f. lag is 90%. Its efficiency at full load, 0.8 p.f. lead will be

More than 90%

80 %

90 %

Less than 90%

TRUE ANSWER : ?
YOUR ANSWER : ?

Ybus used in power flow studies and Zbus used in short circuit studies

Are inverse of each other

Have no inter relation

Are transpose of each other

Are the same

TRUE ANSWER : ?
YOUR ANSWER : ?

The mutual inductance between two unity coupled coils of 9 H and 4 H is

13 H

36 H

2.2 H

6 H

TRUE ANSWER : ?
YOUR ANSWER : ?

Permittivity is expressed in terms of

Farad/m

farad/sq. m.

Weber /m

N/m

TRUE ANSWER : ?
YOUR ANSWER : ?

The circuit breaker generally used in railway traction is

Minimum Oil CB

Air break CB

Vacuum CB

Bulk Oil CB

TRUE ANSWER : ?
YOUR ANSWER : ?

The positive and negative sequence impedance of a transmission line are

Different

Zero

Infinite

Equal

TRUE ANSWER : ?
YOUR ANSWER : ?

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