Power Systems Multiple Choice Questions on “Bundled Conductors”.
1. The larger power can be transmitted over a line with fixed voltage profile when ______
A. compensators are installed
B. negative VAR is fed
C. positive VAR is fed
D. compensators are installed and postive VAR is fed
Answer: D
Clarification: Compensators allow the flow of a large power through the TL by feeding positive VAR into the system.
2. A rectangular voltage wave is impressed on a long overhead line, with the far end of the line being open circuited. After reaching line end, the current is _________
A. current is reflected back with positive but voltage with negative sign
B. current is reflected back with negative but voltage with positive sign
C. both current and voltage are reflected with negative sign
D. both current and voltage are reflected with positive sign
Answer: B
Clarification: For open circuited end, ρ(v) = 1; ρ(i) = -1.
3. A 240 kV 2μs rectangular pulse surge on a transmission line has surge impedance of 350 ohms. It approaches a generating station with capacitance of 3000 pF. The transmitted voltage will be ____________
A. 340.5 kV
B. 280 kV
C. 400 kV
D. 480 kV
Answer: A
Clarification: Vt = 2Vi(1-e(-t/ZC.) = 2*240*1000(1-e-2*10-6/3*350*10-9).
4. In a transmission line system, the feeders act as input to _________
A. distributors
B. service mains
C. transformer sub stations
D. all of the mentioned
Answer: A
Clarification: The feeders have bulk power and they have no tappings. They feed to the distributors.
5. One needs to design the distributors, the parameter which will be considered for the design of it?
A. voltage drop in it
B. current flowing
C. operating voltage
D. operating frequency
Answer: A
Clarification: Distributors work based on the voltage drops measured across them.
6. One would design the feeders of the transmission system based on its ____________
A. current capacity
B. voltage drop
C. operating voltage
D. all of the mentioned
Answer: A
Clarification: Feeders do not have tappings and they are designed on the basis of current flowing through them.
7. The underground transmission and distribution of power is better than the corresponding overhead transmission and distribution in respect of _________
A. appearance and safety
B. maintenance cost
C. frequency of faults
D. appearance, safety, maintenance, frequency
Answer: D
Clarification: All the points are advantageous with respect to overhead transmission line in an underground power transmission system.
8. Before installing any transmission system, one has to decide about the type of the transmission system to be employed. Considering a monetary shortage and economical setup, one would take up _____________
A. underground system
B. overhead system
C. underground or overhead system
D. can be chosen randomly.
Answer: B
Clarification: Underground installation takes a lot of initial cost.
9. The volume of copper required in a transmission system is proportional to _________
A. voltage and power factor
B. power factor
C. voltage
D. current
Answer: A
Clarification: Weight of the copper is proportional to voltage and power factor.
10. While deciding an efficient and economical transmission and distribution system, the preferred distribution system will be _____________
A. single phase, 2 wire
B. two phase, 3 wire
C. three phase, 3 wire
D. three phase, 4 wire
Answer: D
Clarification: For a reliable system, the distribution system should be 4 wire, in case a fault occurs.
11. In India, the preferred poles used in the transmission and distribution is ______
A. Steel poles
B. RCC poles
C. Steel and RCC poles
D. Wood poles
Answer: C
Clarification: The most commonly used poles are steel and RCC poles.
12. Copper has got higher resistivity than aluminium which makes it less used in transmission system.
A. True
B. False
Answer: B
Clarification: Aluminium has higher resistivity over copper.
13. _______ material is used for the making of the ground wire in the transmission system.
A. Galvanised steel
B. Steel
C. Cast iron
D. Aluminium
Answer: A
Clarification: Galvanised steel is used in the ground wire.
14. In emergency cases, another wire is installed in the system, that is widely known as ________________
A. Guy wire
B. Earth wire
C. Line wire
D. Neutral wire
Answer: A
Clarification: Guy wire as the earth route in the emergency earth route.