Govt Exams Mock Test FREE | Online Quiz Competition

Q1. Determine the ohmic value of the current limiting reactor per phase external to a 40 MVA, 15 kV, 50 Hz, three phase synchronous generator which can limit the current on short circuit of 6 times the full load current. The reactance of the synchronous generator is 0.06 pu.

0.4 \(\Omega\)

0.8 \(\Omega\)

0.6\(\Omega\)

0.2 \(\Omega\)

Q2. A 3-phase transmission line operating at \(V_s = 400 kV\) and it's \(ABCD\) parameters \(A= D = 0.9∠0°, B = 100∠°90 \Omega, C = 0.6 \times 10^{-6}∠90° \mho\). Calculate the value of shunt reactor required to compensate the Ferranti effect.

\(1000 \Omega\)

\(500 \Omega\)

\(100 \Omega\)

\(600 \Omega\)

Q3. A 15-bus power system has 4 - voltage controlled buses. For the load flow analysis using Newton-Raphson method in polar coordinates, the size of the Jacobian matrix is__________.

11 * 11

15 * 15

24 * 24

30 * 30

Q4. 100 km long transmission line is loaded at 110 KV. If the loss of line is 5MW and the load is 150MVA, the resistance of the line is

8.06 ohms per phase

0.806 ohms per phase

0.0806 ohms per phase

80.6 ohms per phase

Q5. In a load flow problem solved by Newton-Raphson method with polar coordinates, the size of the Jacobian is 75 x 75. If there are 25 PV buses in addition to PQ buses and a slack bus, the total number of buses in the system is ________.

75

51

76

50

Q6. A 440 V, three-phase, 50 Hz source is feeding a load of 250 kVA at 0.6 pf lagging. Find the kVAR to the capacitor bank required to improve the pf to 0.85 lag.

107 KVAR

307 KVAR

407 KVAR

207 KVAR

Q7. 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

j0.2, j0.05

j0.2, j0.25

j0.25, j0.25

j0.05.i0.05

Q8. A steam power station has an overall efficiency of 20% and 0.6 kg of coal is burnt per kWh of electrical energy generated. The calorific value of fuel is

7166 kcal/kg

5152 kcal/kg

2458 kcal/kg

none of the above

Q9. A 3-phase transmission line is being supported by three disc insulators. The potentials across top unit (i.e., near to the tower) and middle unit are 8 kV and 12 kV respectively. Calculate the ratio of capacitance between pin and earth to the self-capacitance of each unit.

0.5

1.5

0.66

0.33

Q10. A transmission line is compensated with shunt capacitance \(C_{sh}\). If the uncompensated transmission line surge impedance is \(Z_s\), then find the new surge impedance \(Z_s ^{'}\) after shunt compensation.

\(Z_s \times \sqrt{1 + K_{csh}}\)

\(\frac{Z_s} {\sqrt{1 + K_{csh}}}\)

\(\frac {\sqrt{1 + K_{csh}}}{Z_s} \)

all of the above

Quiz

Year 2024

November
Week # 2 Quiz 4

Q1. Determine the ohmic value of the current limiting reactor per phase external to a 40 MVA, 15 kV, 50 Hz, three phase synchronous generator which can limit the current on short circuit of 6 times the full load current. The reactance of the synchronous generator is 0.06 pu.

Q2. A 3-phase transmission line operating at \(V_s = 400 kV\) and it's \(ABCD\) parameters \(A= D = 0.9∠0°, B = 100∠°90 \Omega, C = 0.6 \times 10^{-6}∠90° \mho\). Calculate the value of shunt reactor required to compensate the Ferranti effect.

Q3. A 15-bus power system has 4 - voltage controlled buses. For the load flow analysis using Newton-Raphson method in polar coordinates, the size of the Jacobian matrix is__________.

Q4. 100 km long transmission line is loaded at 110 KV. If the loss of line is 5MW and the load is 150MVA, the resistance of the line is

Q5. In a load flow problem solved by Newton-Raphson method with polar coordinates, the size of the Jacobian is 75 x 75. If there are 25 PV buses in addition to PQ buses and a slack bus, the total number of buses in the system is ________.

Q6. A 440 V, three-phase, 50 Hz source is feeding a load of 250 kVA at 0.6 pf lagging. Find the kVAR to the capacitor bank required to improve the pf to 0.85 lag.

Q7. 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

Q8. A steam power station has an overall efficiency of 20% and 0.6 kg of coal is burnt per kWh of electrical energy generated. The calorific value of fuel is

Q9. A 3-phase transmission line is being supported by three disc insulators. The potentials across top unit (i.e., near to the tower) and middle unit are 8 kV and 12 kV respectively. Calculate the ratio of capacitance between pin and earth to the self-capacitance of each unit.

Q10. A transmission line is compensated with shunt capacitance \(C_{sh}\). If the uncompensated transmission line surge impedance is \(Z_s\), then find the new surge impedance \(Z_s ^{'}\) after shunt compensation.

Quiz

Year 2024

December Week # 1 Expire on 31 Dec 2024

December Week # 2 Expire on 07 Jan 2025

December Week # 3 Expire on 14 Jan 2025

December Week # 4 Expire on 21 Jan 2025

November Week # 2 Quiz 4

Q1. Determine the ohmic value of the current limiting reactor per phase external to a 40 MVA, 15 kV, 50 Hz, three phase synchronous generator which can limit the current on short circuit of 6 times the full load current. The reactance of the synchronous generator is 0.06 pu.

Q2. A 3-phase transmission line operating at \(V_s = 400 kV\) and it's \(ABCD\) parameters \(A= D = 0.9∠0°, B = 100∠°90 \Omega, C = 0.6 \times 10^{-6}∠90° \mho\). Calculate the value of shunt reactor required to compensate the Ferranti effect.

Q3. A 15-bus power system has 4 - voltage controlled buses. For the load flow analysis using Newton-Raphson method in polar coordinates, the size of the Jacobian matrix is__________.

Q4. 100 km long transmission line is loaded at 110 KV. If the loss of line is 5MW and the load is 150MVA, the resistance of the line is

Q5. In a load flow problem solved by Newton-Raphson method with polar coordinates, the size of the Jacobian is 75 x 75. If there are 25 PV buses in addition to PQ buses and a slack bus, the total number of buses in the system is ________.

Q6. A 440 V, three-phase, 50 Hz source is feeding a load of 250 kVA at 0.6 pf lagging. Find the kVAR to the capacitor bank required to improve the pf to 0.85 lag.

Q7. 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

Q8. A steam power station has an overall efficiency of 20% and 0.6 kg of coal is burnt per kWh of electrical energy generated. The calorific value of fuel is

Q9. A 3-phase transmission line is being supported by three disc insulators. The potentials across top unit (i.e., near to the tower) and middle unit are 8 kV and 12 kV respectively. Calculate the ratio of capacitance between pin and earth to the self-capacitance of each unit.

Q10. A transmission line is compensated with shunt capacitance \(C_{sh}\). If the uncompensated transmission line surge impedance is \(Z_s\), then find the new surge impedance \(Z_s ^{'}\) after shunt compensation.

Record & Track Your Performance

November
Week # 2 Quiz 4