250+ TOP MCQs on Inductance of Composite Conductor Lines – 3 and Answers

Power Systems Interview Questions on “Inductance of Composite Conductor Lines – 3”.

1. A single phase 50 hz, generator supplies an inductive load of 5 MW at a power factor of 0.8 lagging using OHTL over 20 km. The resistance and reactance are 0.39Ω and 3.96 Ω. The voltage at receiving station is maintained at 10 KV. The sending end voltage is 11.68 kV. The voltage regulation will be _______
A. 16.8 %
B. 18.8%
C. 21.75%
D. 12.8%

Answer: A
Clarification: VR = (11.68-10)*100/10 = 16.8 %.

2. A single phase 50 hz, generator supplies an inductive load of 5 MW at a power factor of 0.8 lagging using OHTL over 20 km. The resistance and reactance are 0.39Ω and 3.96 Ω. The voltage at receiving station is maintained at 10 KV. Identify the transmission line and the voltage regulation.
A. STL, 11.68%
B. MTL, 11.68
C. STL, 21.5%
D. MTL, 14.2%

Answer: A
Clarification: It is a short transmission line.
Current, I = 5000/(10*0.8)=625 A
V_s = |V_r|+|I|*(RcosФ_r + XsinФ_r)
= 10000+625(0.39*0.8+3.96*0.6)
= 11.68kV
VR = (11.68-10)*100/10 = 16.8 %.

3. A single phase 50 hz, generator supplies an inductive load of 5 MW at a power factor of 0.8 lagging using OHTL over 20 km. The resistance and reactance are 0.39Ω and 3.96 Ω. The voltage at receiving station is maintained at 10 KV. The sending end voltage is 11.68 kV. The half the voltage regulation will be _____________
A. 8.4 %
B. 16.8 %
C. 14.2%
D. 10.5%

Answer: A
Clarification: VR = (11.68-10)*100/10 = 16.8 %
Half the VR = 16.8/2 % = 8.4%.

4. A single phase 50 hz, generator supplies an inductive load of 5 MW at a power factor of 0.8 lagging using OHTL over 20 km. The resistance and reactance are 0.39Ω and 3.96 Ω. The voltage at receiving station is maintained at 10 KV. The sending end voltage is 11.68 kV. The new sending end voltage at the half the voltage regulation is _____________
A. 10.84 kV
B. 11.84 kV
C. 8.84 kV
D. 16.2 kV

5. A single phase 50 hz, generator supplies an inductive load of 5 MW at a power factor of 0.8 lagging using OHTL over 20 km. The resistance and reactance are 0.39Ω and 3.96 Ω. The voltage at receiving station is maintained at 10 KV. The sending end voltage is 11.68 kV. If the voltage regulation is reduced to 50%, then the power factor at this operation mode will be _________________
A. 0.95
B. 0.92
C. 0.74
D. 0.90

6. A single phase 50 hz, generator supplies an inductive load of 5 MW at a power factor of 0.8 lagging using OHTL over 20 km. The resistance and reactance are 0.39Ω and 3.96 Ω. The voltage at receiving station is maintained at 10 KV. The sending end voltage is 11.68 kV. If the voltage regulation is reduced to 50%, then the power factor angle at this operation mode will be _____________
A. 18.04°
B. 8.04°
C. 21.06°
D. 12°

7. A single phase 50 hz, generator supplies an inductive load of 5 MW at a power factor of 0.8 lagging using OHTL over 20 km. The resistance and reactance are 0.39Ω and 3.96 Ω. The voltage at receiving station is maintained at 10 KV. The sending end voltage is 11.68 kV. If the voltage regulation is reduced to 50%, then the power factor at this operation mode will be ____________
A. 0.95, lagging
B. 0.92, leading
C. 0.95, lagging
D. 0.90, leading

8. A single phase 50 hz, generator supplies an inductive load of 5 MW at a power factor of 0.8 lagging using OHTL over 20 km. The resistance and reactance are 0.39Ω and 3.96 Ω. The voltage at receiving station is maintained at 10 KV. The sending end voltage is 11.68 kV. If the voltage regulation is reduced to 50%, then the power factor angle at this operation mode will be ________
A. 18.04°, lagging
B. 18.04°, leading
C. 21.06°, leading
D. 21.06°, lagging

9. A single phase 50 hz, generator supplies an inductive load of 5 MW at a power factor of 0.8 lagging using OHTL over 20 km. The resistance and reactance are 0.39Ω and 3.96 Ω. The voltage at receiving station is maintained at 10 KV. The sending end voltage is 11.68 kV. If the voltage regulation is reduced to 50%, then the receiving end current at this operation mode will be _____________
A. 526 A
B. 549 A
C. 521 A
D. 580 A

10. Suppose the transmission line is loaded with its surge impedance, the receiving-end voltage is greater than sending end voltage.
A. True
B. False

Answer: B
Clarification: It will be equal.