BARC EE : Power System Quiz-1

If line inductance is 10 mH/m and line capacitance is 100 μF/m. Then the surge impedance of line is __________Ω.

Calculate the current I_d in the relay coil shown in the below figure

The corona loss in a 50 Hz system is 0.2 kW/phase/km. The corona loss at a frequency of 70 Hz will be:

For a single core cable insulation resistance is 5 MΩ/km. For 5 km length, insulation resistance is ______MΩ.

Which of the following statements is/are correct regarding grading of insulators?

1) Equalization of voltage drop across the units.

2) It protects the insulator string from flash over.

A 3-phase generator with a phase emf of 1.0 p.u. and with positive, negative and zero sequence reactance’s of 0.2 p.u., 0.15 p.u., respectively. It has a grounding reactance of 0.05 p.u. If a single line to ground fault occur at the terminal of generator, then fault current is:

String efficiency is _______% having 4 units and voltage across the bottom most unit is 0.33 times of total voltage.

When the sinusoidal steady state current is called the symmetrical short circuit current, then the unidirectional transient component is called