GATE EE 2021 : Power System Revision Quiz 6 (App update required to attempt this test) for ESE & GATE EE Exams

Question 1

Which of the following are peak load power plants

Question 2

For a constant load having load angle of 30

if the excitation of the alternator is increased by 30% then calculate the new load angle for this system?

Question 3

Which of the following component of the hydroelectric plant prevents the entry of any water-borne debris to enter the power generation unit?

Question 4

In case of fully transposed transmission line

Question 5

For what purpose is graphite used in a nuclear power plant?

Question 6

A synchronous generator rated 400 kVA, 400 V, 0.2 p.u. sub transient reactance is supplying a passive load of 200 kW at 0.8 lagging power factor. If a three-phase fault occurs at generator terminals, then the magnitude of initial symmetrical fault current is:

Question 7

A 100 MVA, 33 kV,3 phase synchronous generator was subjected to different type of faults. The fault current are as follows

LG fault = 4500 A

LL fault = 2800 A

3 phase fault = 2100 A

The generator neutral is solidly grounded. The value of the zero sequence reactance of the generator is

Question 8

Three identical unloaded alternator are connected in parallel as shown below.

All the generator has positive, negative and zero sequence impedance of j0.6p.u., j0.3p.u. and j0.1p.u. respectively. If the pre-fault voltage is 1p.u., for a line to ground (LG) fault at the terminals of the generators, the fault current in p.u. is

Question 9

A 400 MVA, 11 kV, 50 Hz synchronous generator having X_d^`` = 0.1 p.u is supplying a passive load of 200 MW at 11 kV. The load is purely resistive. Then the value of post fault current at generator terminal is

Question 10

A LLL fault occurs at terminals of a 33 kV, 3 phase 50 Hz circuit breaker. The maximum value of restriking voltage across the breaker is

Question 11

A three phase Y-connected alternator rated as 10 MVA , 13.8 kV has following sequence reactance
Negative sequence reactance= 40%
Positive sequence reactance= 30%
Zero sequence reactance= 5%
A reactance X_n is to be added in the generator neutral such that the fault current for a line-to-ground fault of zero fault impedance will not exceed the rated line current. The per unit value of X_n is

Question 12

A short 3-ϕ transmission line connected to a 33 kV, 50 Hz generating station at the sending end is required to supply a load of 8 MW at 0.8 power factor lagging at 30 kV at the receiving end. If the minimum transmission efficiency is to be limited to 95%. Find the value of inductance of line.

Question 13

A long lossless transmission line has a unity power factor load at receiving end and an A .C. voltage source at the sending end, parameter of transmission lines are: Z_C = 400 Ω , β = 1.2×10^–3 rad/km & l = 200 km. Calculate the maximum power that can be transferred to a unity power factor load at receiving end, if |V_S| = 440 kV.

Question 14

Assume a 275 kV transmission line having the following line constants:A = 0.8∠5° ; B = 200∠75°.
If a load is connected at receiving end at unity power factor but maintaining the same voltage profile. Then _________ compensation will be needed at ______

Question 15

Two generator G₁ and G₂ are rated as 500 MW and 400 MW respectively are operating in parallel. The drooping characteristics of both generators are 5 % and 4 % respectively from no-load to full load, with no load frequency of 60 Hz. If 800 MW is being shared by both the generators, then determine the frequency of operation.