Year 2024

Week # 2 Quiz 5

Q1. A string type insulator has \(4\) units with self capacitance \(C\) and shunt capacitance of \(0.3 \times C\). Find the string efficiency.

Q2. When a 50MVA ,11KV , 3-phase generator is subjected to a 3-phase fault, the fault current is -j5 p.u.. When it is subjected to line-line fault, the positive sequence current is -j4 p.u.. The positive and negative sequence reactances are respectively

Q3. If the severity of single line-to-ground fault at the terminals of an unloded star connected synchronous generator is greater than that of 3-phase faults, then _______ where, \(X_1\) is the positive sequence reactance of the generator, \(X_{g0}\) is the zero sequence reactance of the generator and \(X_n\) is the neutral reactance.

Q4. A cable has inductance of \(0.22 \: mH/km\) and capacitance of \(0.202 \: \mu F/km\). The surge impedance of the cable is

Q5. Three unequal impedances are fed by a balanced 3-phase system through 3-phase 3 wire system. The impedances are connected in star. The sum of three line currents is

Q6. The capacitance per kilometer of 3-phase belted cable is 0.09 F between the two cores with the third core connected to the lead sheath. Determine the core to neutral capacitance for the 5 km long cable.

Q7. Burden of a protective relay is the power

Q8. A transmission line has a reactance of \(1 \: pu\) is operating at \(V_s=V_r=1 \:pu\). The generator is connected at source end which is delivering \(1 \: pu\) of active power and the transmission line is compensated with a series capacitance of \(0.5 \: pu\). Find the load angle with series capacitance compensation?

Q9. A photovoltaic panel has four modules connected in series, each module having an open circuit voltage \(V_{oc}\) of 12 V and short circuit current \(I_{sc}\) of 2A. What should be the current axis intercept of the IV characteristics of the series system?

Q10. Reheat cycle in steam power plant is used to