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Corona MCQ's Interview Questions.

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Q.1 Corona is-

A. Partial breakdown of air
B. Complete breakdown of air
C. Sparking between lines
D. None of these
Ans: B

Q.2 Which of the following statements is true regarding corona-

A. Corona takes place at a voltage lower than breakdown voltage
B. Corona takes place at a voltage higher than breakdown voltage
C. Corona is a current phenomenon
D. Corona increases the transmission line efficiency
Ans: A

Q.3 Corona is accompanied by-

A.Violet visible discharge in darkness
B. Hissing sound
C. Vibration
D. Power loss
E. Radio interference
F. Ozone
G. All of the above
Ans: G
 

Q.4 Ozone effect can be detected by

A. Presence of ozone detected by odour
B. Hissing sound
C. Faint luminous glow of bluish colour
D. All of the above
Ans: D

Q.5 Corona loss increases with

A. Decrease in conductor size and increase in supply frequency
B. Increase in conductor size and decrease in supply frequency
C. Increase in both conductor size and supply frequency
D. Decrease in both conductor size and supply frequency
Ans: A

Q.6 The good effect of corona on overhead lines is to

A. Increase the lie carrying capacity due to conducting ionized air envelope around conductor
B. Increase the power factor due to corona loss
C. Reduce the radio interference from the conductor
D. Reduce the steepness of surge fronts
Ans: D

Q.7 Corona loss can be reduced by the use of hollow conductor because

A. The current density is reduced
B. The eddy current in the conductor is eliminated
C. For a given cross section, the radius of the conductor is increased
D. Of better ventilation in the conductor
Ans: C

Q.8 Bundled conductors reduce

A. Surface electric stress of conductor
B. Increases the line reactance
C. Decrease the line capacitance
D. All
Ans: A


Q.9 Corona loss in a transmission line is dependent on


A. Diameter of the conductor
B. Material of the conductor
C. Height of the conductor
D. None
Ans: A

Q.10 Corona occurs between two transmission conductors when they

A. Have high potential difference
B. Are closely spaced
C. Carry dc power
D. Both A and B

Ans: D
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