Power System - II (3150911) MCQs

MCQs of Unsymmetrical Fault Analysis

Showing 11 to 20 out of 31 Questions
11.
A single line to ground fault occurs on a three-phase isolated neutral system with a line to neutral voltage of V kV. The potentials on the healthy phases rise to a value equal to
(a) √2V kV
(b) √3V kV
(c) 3V kV
(d) (1 ∕√3)V kV
Answer:

Option (b)

12.
If all the sequence voltages at the fault point in a power system are equal, then the fault is a
(a) Three-phase fault
(b) Line to ground fault
(c) Line to line fault
(d) Double line to ground fault
Answer:

Option (d)

13.
The zero sequence current of a generator for line to ground fault is j2.4 pu. Then the current through the neutral during the fault is
(a) j2.4 pu
(b) j0.8 pu
(c) j7.2 pu
(d) j0.24 pu
Answer:

Option (c)

14.
The severity of line to ground and three-phase faults at the terminals of an unloaded synchronous generator is to be same. If the terminal voltage is 1.0 pu, Z1 = Z2 = j0.1 pu and Z0 = j0.05 pu for the alternator, then the required inductive reactance for neutral grounding is
(a) 0.0166 pu
(b) 0.05 pu
(c) 0.1 pu
(d) 0.15 pu
Answer:

Option (a)

15.
The most frequently occurring fault in the power system is
(a) Line to ground fault
(b) Line to line fault
(c) Double line to ground fault
(d) Three-phase fault
Answer:

Option (a)

16.
In which type of fault, all the three components Ia0, Ia1, and Ia2 are equal Ia0
(a) line to ground fault
(b) line to line fault
(c) double line to ground fault
(d) None of the above
Answer:

Option (a)

17.
When a line-to-ground fault occurs, the current in a faulted phase is 100 A. The zero sequence current in this case will be
(a) Over voltage on line due to charged cloud
(b) Line to line fault
(c) 3-phase fault
(d) Double line to ground fault
Answer:

Option (d)

18.
In which type of fault, positive sequence and negative sequence voltages are equal
(a) Line to line fault
(b) Double line to ground fault
(c) Line to ground fault
(d) None of the above
Answer:

Option (b)

19.
For the fault analysis in power system, symmetrical components are used because
(a) Results are required in terms of symmetrical components
(b) Sequence network do not have mutual coupling
(c) Number of equations becomes smaller
(d) All of above
Answer:

Option (b)

20.
Choose the correct one from the statement given
(a) There is a minimum sequence voltage and maximum negative sequence voltage at the fault point
(b) Zero and negative sequence voltages are maximum at fault point towards neutral
(c) Zero sequence and negative sequence voltages are minimum at fault point and increase towards neutral
(d) None of the above
Answer:

Option (b)

Showing 11 to 20 out of 31 Questions