Quiz

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Year 2024

July
Week # 2 Quiz 4

Q1. A transmission line has surge impedance of \(400 \Omega\), The sending end and receiving end voltage are \(V_s = V_r = 400 kV\). The line is compensated with a shunt capacitance of \(25\%\). The line is connected to a generator with delivering power of \(300 MW\). Find the load angle without and with compensation respectively.

Q2. The network shown in Fig. has impedance in p.u. as indicated. The diagonal element \(Y_{22}\) of the bus admittance matrix \(Y_{bus}\) of the network is _______.



Q3. The surge impedance loading of a 500 km long, 400 KV transmission line is 400 ohms. The SIL(Surge Impedance Loading) is__________.

Q4. A circuit breaker is rated at 1500 amps, 2000 MVA, 33 kV, 3 sec, 3- phase, oil circuit breaker. Determine the breaking current and making current.

Q5. A shunt capacitor at 100 MVAr is operated at 105% of its rated voltage and at 98% of its rated frequency. The reactive power produced by the capacitor is

Q6. In case of interconnected power system, if the input to the prime mover of an alternator is kept constant but the excitation is changed, then the

Q7. An overhead line having a surge impedance of 400 ohm is connected in series with an underground cable having a surge impedance of 100 ohm. If a surge of 50 kV travels from the line towards the cable junctions, the value of the transmitted voltage wave at the junction is

Q8. A string insulator has \(5\) units. The string efficiency is \(75\%\). Find the voltage across the bottom most unit with reference to string voltage.

Q9. At an Industrial substation with a 4 MW load a capacitor of 3 MVAR is installed to maintain the load power factor at 0.97 lag. If the capacitor goes out of service, the load power factor becomes

Q10. The current flowing in to a balanced delta connected load through line 'a' is 10 A when the conductor of line 'b' is open. With the current in line 'a' as reference, compute the symmetrical components of the line currents. Assume the phase sequence of 'abc'.