1. The minimum phase neutral voltage at which Corona occurs is called
(a) knee voltage.
(b) flash over voltage.
(c) critical disruptive voltage.
(d) visual critical voltage.
Answer
2. For constant voltage transmission the voltage drop is compensated by installing
(a) synchronous motors.
(b) capacitors.
(c) inductors.
(d) all of the above.
Answer
3. Transposition of transmission line is done to
(a) decrease I2R losses.
(b) decrease corona effect.
(c) balance line voltage.
(d) decrease skin effect.
Answer
4. Strain type insulator are used where the conductors are
(a) dead ended.
(b) at intermediate anchor towers.
(c) any of the above.
(d) none of the above.
Answer
5. Disc type insulators are used for voltage beyond
(a) 11 kV.
(b) 33 kV.
(c) 66 kV.
(d) 132 kV.
Answer
6. Corona in transmission line will result in
(a) increase energy loss.
(b) increase reactance.
(c) increase inductance.
(d) all of the above.
Answer
7. Corona effect can be detected by
(a) hissing sound.
(b) faint luminous flow of bluish color.
(c) presence of ozone detected by odor.
(d) all of the above.
Answer
8. In transmission line production of ozone resulted by corona is harmful because
(a) it gives bad odor.
(b) it corrodes the material.
(c) it transfers energy to the ground.
(d) reduces power factor.
Answer
9. Which class of insulators has high maximum working temperature?
(a) B – class.
(b) F – class.
(c) C – class.
(d) Y – class.
Answer
10. The skin effect of a conductor will reduce as the
(a) resistivity of conductor increases.
(b) permeability of conductor increases.
(c) diameter increases.
(d) frequency increases.
Answer
11. The current drawn by the line due to corona losses is
(a) non-sinusoidal.
(b) sinusoidal.
(c) triangular.
(d) square.
Answer
12. A line which connects between substation and distribution transformer is
(a) secondary feeder.
(b) primary feeder.
(c) sub transmission feeder.
(d) none of these.
Answer
13. Which of the following distribution system is most reliable?
(a) Ring main system.
(b) Parallel system.
(c) Radial system.
(d) All are equal.
Answer
14. Specific gravity of Al is
(a) 1.5
(b) 2.7
(c) 4.2
(d) 7.8
Answer
15. For transmission of power over a distance of 200 km, the transmission voltage should be
(a) 132 kV
(b) 66 kV
(c) 33 kV
(d) 11 kV