### MCQs of Symmetrical Fault Analysis

Showing 1 to 10 out of 55 Questions
1.
The pu impedance value of an alternator corresponding to base values 13.2 kV and 30 MVA is 0.2 pu. The pu value for the base values 13.8 kV and 50 MVA will be
 (a) 0.306 pu (b) 0.33 pu (c) 0.318 pu (d) 0.328 pu
2.
In case of a 3-phase short circuit in a system, the power fed into the system is
 (a) Mostly reactive (b) Mostly active (c) Active and reactive both equal (d) Reactive only
3.
If α is the angle of voltage wave at which an R-L circuit is switched in and Θ is the impedance angle of the R-L circuit, there will be no transient when the circuit is switched in, if
 (a) α = Θ (b) α = 90 – Θ (c) α = 90 + Θ (d) None of the above
4.
An RLC series circuit remains predominantly inductive
 (a) At resonance frequency (b) Below resonance frequency (c) Above resonance frequency (d) At the lower half power frequency
5.
If a synchronous machine is overexcited, it takes lagging VAR from the system when it is operated as a
 (a) Synchronous motor (b) Synchronous generator (c) Synchronous motor as well as generator (d) None of the above
6.
If a synchronous machine is under excited it takes lagging VAR from the system when it is operated as a
 (a) Synchronous motor (b) Synchronous generator (c) Synchronous motor as well as generator (d) None of the above
7.
A synchronous machine has higher capacity for
 (a) Leading power factor (b) Lagging power factor (c) It does not depend upon the power factor of the machine (d) It depends upon the power factor of the load
8.
A transformer rated for 500 KVA, 1 KV/0.4 KV has an impedance of 10% and is connected to an infinite bus. The fault level of the transformer is
 (a) 500 KVA (b) 5000 KVA (c) √3x500 KVA (d) None of the above
9.
In a large interconnected power system, consider three buses having short-circuit capacities 1500 MVA, 1200 MVA and 1000 MVA respectively. The voltages of all the buses are 1.0 pu. If a 3-phase fault takes place on bus 2, the change in bus voltage is described as
 (a) ΔV1 > ΔV2 > ΔV3 (b) ΔV1 < ΔV3 < ΔV2 (c) ΔV1 > ΔV3 > ΔV2 (d) None of the above
10.
A power system network with a capacity of 100 MVA has a source impedance of 10% at a point. The fault level at that point is
 (a) 10 MVA (b) 30 MVA (c) 3000 MVA (d) 1000 MVA
Showing 1 to 10 out of 55 Questions