Power Systems Multiple Choice Questions on “Capacitance of a Two-Wire Line”
1. The presence of ozone while the corona has occurred, can be found using ________
A. pressure
B. hissing noises
C. faint luminous glow of bluish colour
D. all of the mentioned
Answer: D
Clarification: The ozone can be easily detected by all the mentioned effects occurring in the system.
2. The corona has only disadvantages to the transmission system.
A. True
B. False
Answer: B
Clarification: Corona is helpful while the surges are there.
3. The very peculiar advantage of corona in the circuit can be ___________
A. reduction in steepness of surge fronts
B. improvement of power factor
C. reduction in radio interference
D. reduction in steepness, radio interference and improvement of PF
Answer: A
Clarification: Corona reduces the surge occurring in the system.
4. When the ozone gas is produced as a by product of corona, that causes _______
A. corrosion of wires
B. reduction of power factor
C. increase of power factor
D. improvement of regulation
Answer: A
Clarification: Ozone gas corrodes the metals.
5. Critical voltage limit of the transmission line can be increased by ____________
A. increasing conductor’s radius
B. increasing conductor spacing
C. reducing conductor spacing
D. reducing radius of conductor
Answer: A
Clarification: Vα 1/r.
6. In a transmission system, the transmission parameters of distribution is/are ___________
A. resistance
B. inductance
C. capacitance and shunt conductance
D. resistance, inductance, capacitance and shunt conductance
Answer: D
Clarification: R, L, C, G are the distribution constants.
7. Following effects of the transmission lines
(i) Skin effect
(ii) Corona
(iii) Proximity
The effective resistance of the conductor is increased by __________
A. (i), (ii)
B. (i), (iii)
C. (ii), (iii)
D. (i), (ii), (iii)
Answer: D
Clarification: Effective resistance increases by skin effect, corona as well as proximity effect.
8. _______ is neglected while carrying out short transmission line analysis.
A. Shunt admittance
B. Power losses
C. Series impedance
D. None of the mentioned
Answer: A
Clarification: Shunt admittance is neglected.
9. We transpose high voltages especially while transmitting so that the __________
A. phase voltage imbalances can be minimised
B. corona losses are reduced
C. voltage drop is minimised
D. all of the mentioned
Answer: A
Clarification: Transposition reduces the phase voltage imbalances by cancelling their effects.
10. While modelling a short transmission line of the overhead lines, line resistance and inductances are only considered because the line capacitance is ___________
A. zero
B. finite but small
C. finite but large
D. infinite
Answer: B
Clarification: Capacitance for such a distance is small and negligible.