1. The generating voltage and frequency in India is about?
A. 11 kV and 60 Hz
B. 11 kV and 50 Hz
C. 220 kV and 60 Hz
D. 220 kV and 50 Hz
Answer: B. 11 kV and 50 Hz
2. Which type of system is generally adopted for the generation and transmission of electrical power?
B. 2 phase 3 wire
C. 3 phase 3 wire
D. None of these
Answer : C. 3 phase 3 wire
3. The rated voltage of a 3 phase power system is given by ____________.
B. Peak phase voltage
C. RMS line to line voltage
D. Peak line to line voltage
Answer : C. RMS line to line voltage
4.Which of these systems uses the 3 phase 4 wire system?
B. Secondary distribution
C. Primary transmission
D. Secondary transmission
Answer: B. Secondary distribution
5. With the same maximum voltage to earth, which among the following AC systems with 0.8 pf will need more copper compared to 2 wire system?
B. Single-phase, 3 wire
C. Three-phase, 3 wire
D. Three-phase, 4 wire
Answer: D. Three-phase, 4 wire
6. In a transmission system, the weight of copper used is proportional to
B. Voltage
C. 1 / (square of voltage)
D. 1 / voltage
Answer:C. 1 / (square of voltage)
7. Greater the power factor the ________________ is the volume of copper required.
B. Smaller
C. Both are equal
D. Depending of the level of transmission
Answer: B. Smaller
8. Line efficiency increases for ________ transmission voltages.
B. Lower
C. Both (A) and (B)
D. None of these
Answer: A. Higher
9. The most important disadvantage of using the high voltage for transmission is
B. The increased cost of transformers, switchgear and the other terminal apparatus.
C. Both (A) and (B)
D. There is a reduction in the corona loss.
Answer: C. Both (A) and (B)
10. The most suitable practical value of the primary distribution is?
B. 6.6 kV
C. 230 V/ 400 V
D. 22 kV
Answer:B. 6.6 kV
11. What is the main drawback of the overhead system over the underground system?
B. High initial cost
C. Higher charging current
D. The underground system is more flexible than the overhead system
Answer: A. Surge problem
12. For the same conductor length, same amount of power, same losses and maximum voltage to earth, which system requires minimum conductor area?
B. 2 wire ac
C. 2 wire dc
D. Single-phase
Answer: A. 3 wire ac
13. What is the highest possible transmission voltage in India?
B. 765 kV
C. 132 kV
D. 440 kV
Answer: B. 765 kV
14. What is the main reason for using the high voltage for the long distance power transmission?
B. Reduction in the time of transmission
C. Increase in system reliability
D. None of these
Answer: A. Reduction in the transmission losses
15. By increasing the transmission voltage double of its original value, the same power can be despatched keeping the line losses _______________.
B. Half of its original value.
C. Double the original value.
D. One-fourth of the original value.
Answer: D. One-fourth of the original value.
16. Which among these is/are the fundamental economical principles that influence/s the design of transmission lines?
B. Economic choice of transmission voltage.
C. Both (A) and (B)
D. Economic choice of transmission line length.
Answer: C. Both (A) and (B)
17. The most economical area of conductor is that for which the total annual cost of transmission line is minimum. Which law states this?
B. Kelvin’s law
C. Faraday’s law
D. Ohm’s law
Answer: Kelvin’s law
18. The account of interest and depreciation on the capital cost of complete installation of transmission line is denoted by which factor?
B. The annual cost of energy wasted
C. Both (A) and (B)
D. Neither of these
Answer:A. Annual charge on capital outlay
19. Which among these is not the component of overhead transmission lines?
A. Conductors
B. Cross arms
C. Danger plates
D. Transformers
Answer: D. Transformers
20. Which among these properties are not suitable for the conductor material?
A. High electrical conductivity.
B. High specific gravity.
C. Lower cost.
D. High tensile strength.
Answer: B. High specific gravity.