Explore topic-wise MCQs in Electrical Engineering (MCQ) questions and answers.

This section includes 14 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering (MCQ) questions and answers knowledge and support exam preparation. Choose a topic below to get started.

1.

A 50 Hz, 11 kV, 3 phase alternator with earthed neutral having a reactance of 3 ohms per phase and is connected to a bus bar through a circuit breaker, if the distributed capacitance upto CB between the phase and neutral is 0.01 F.What is the frequency of oscillations?

A. 10000 Hz
B. 12500 Hz
C. 12628 Hz
D. 13265 Hz
Answer» D. 13265 Hz
Discussion
2.

In a short circuit test on a circuit breaker, the following readings were obtained on single frequency transients

A. 100 Hz
B. 1,000 Hz
C. 10,000 Hz
D. 10 Hz
Answer» D. 10 Hz
Discussion
3.

A 50 Hz, 11 kV, 3 phase alternator with earthed neutral having a reactance of 3 ohms per phase and is connected to a bus bar through a circuit breaker, if the distributed capacitance upto CB between the phase and neutral is 0.01 F.What is the peak re striking voltage?

A. 18.36 kV
B. 17.96 kV
C. 15.96 kV
D. 12.65 kV
Answer» C. 15.96 kV
Discussion
4.

A 50 Hz 3 phase synchronous generator has inductance per phase of 15mH. The capacitance of generator and the circuit breaker is 0.002 F. What is the natural frequency of oscillation?

A. 29 kHz
B. 2.9 kHz
C. 290 kHz
D. 29 MHz
Answer» B. 2.9 kHz
Discussion
5.

For the following figure shows a CB circuit with L - C introducing a damping circuit. For the critical damping what is the value of r?

A. (LC)
B. 0.5* (C/L)
C. 0.5* (L/C)
D. 2 * (L/C)
Answer» D. 2 * (L/C)
Discussion
6.

What is the normal pressure at which the SF gas is maintained in the closed position of the breaker?

A. 2 kg / cm
B. 2.5 kg /cm
C. 2.8 kg / cm
D. 3 kg / cm
Answer» D. 3 kg / cm
Discussion
7.

What is the most important property which makes the SF very efficient medium for circuit breaking?

A. Is non toxic and non inflammable.
B. Has a high dielectric constant.
C. Has a high breakdown strength
D. Is highly electronegative gas
Answer» E.
Discussion
8.

SF gas is imported in _____________.

A. Air cylinders
B. Gas cylinders
C. Liquid form in cylinders
D. Solid form.
Answer» D. Solid form.
Discussion
9.

Assertion (A): In comparison to making capacity of a circuit breaker its breaking capacity is normally higher.Reason (R): The breaking capacity of a CB is expressed as 3 * VI * 10 MVA

A. Both A and R are true and R is the correct explanation of A
B. Both A and R are true and R is not the explanation of A
C. A is true but R is false
D. A is false but R is true.
Answer» E.
Discussion
10.

SF is which type of gas?

A. Electro positive
B. Electro negative
C. Both (a) and (b)
D. None of these
Answer» D. None of these
Discussion
11.

In the following figure, the tripping circuit is__________.

A. AC
B. DC
C. Either AC or DC
D. None of these
Answer» D. None of these
Discussion
12.

In the following figure, which component ensures the safety of the line from damage?

A. Relay
B. Circuit breaker
C. Bus bar
D. Current transformer
Answer» B. Circuit breaker
Discussion
13.

In the following figure, the relay circuit is divided into three parts. What does the third part consist of?

A. Primary winding of a current CT which is connected in series with the line to be protected.
B. Secondary of the CT and the operating coil.
C. Tripping circuit.
D. None of these
Answer» D. None of these
Discussion
14.

In the following figure, the relay circuit is divided into three parts. What does the first part consist of?

A. Primary winding of a current CT which is connected in series with the line to be protected.
B. Secondary of the CT and the operating coil.
C. Tripping circuit.
D. None of these
Answer» B. Secondary of the CT and the operating coil.
Discussion