MGVCL Exam Paper (30-07-2021 Shift 3)
The complex power injections at a bus are shown in figure Two lines connected drawing the powers as shown in figure. The complex power in the line-2 "S2" is
Die-electric test on Circuit breaker: These tests are performed to check power frequency and impulse voltage withstand capacity. Power frequency tests are kept on a new circuit breaker, the test voltage changes with a circuit breaker rated voltage. In impulse tests, impulse voltage of particular value is employed to the breaker.
A coil having large number of turns of fine wire is wound on the middle limb of the shunt magnet. This coil is known as pressure or voltage coil and is connected across the supply mains. The voltage coil produces a high ratio of inductance to resistance.
After closing switch, Capacitor is behave as short circuit element, So, I(to) = V/R = 10/5 2 At t = infinite time capacitor is behave as open circuit, I(t) = I(to)e^(-t/Ƭ) Ƭ = time constant of circuit Ƭ = R*C = 200 μF I(t) = 5*e^(-t/(500*10^(-6)) = 5*e^(-5000t) A
1.6 inches = 1.6 inches x 1,000 mils per inch = 1,600 mils 0.25 inch = 0.25 inch x 1,000 mils per inch = 250 mils Area = 1,600 x 250 = 400,000 square mils