MCQs of Corona (Power System - II - 3150911)

Showing 21 to 30 out of 47 Questions

21.

Compared with a solid conductor of the same radius, corona appears on a standard conductor at a lower voltage because stranding

(a)	Assists in ionization
(b)	Make the current flow spiral about axis of conductor
(c)	Produces oblique section to a plane perpendicular to axis of conductor
(d)	Produces surface of smaller radius

22.

Corona loss by the hollow conductors because

(a)	Current density is reduced
(b)	Eddy current in the conductor is eliminated
(c)	For a given cross section, radius of conductor is increased
(d)	Of better ventilation in the conductor

23.

To reduce corona effect usually

(a)	Distance between the conductor is reduced
(b)	Conductor diameter is reduced
(c)	Bundled conductors are used
(d)	Stranded conductors are used

24.

Bundled conductors reduce

(a)	Surface electric stress of conductor
(b)	Line reactance
(c)	Line capacitance
(d)	None of above

25.

Corona loss in a transmission line is dependent on

26.

Corona occurs between two transmission conductor when they

(a)	Have high potential difference
(b)	Are closely spaced
(c)	Carry DC power
(d)	Both (a) and (b)

27.

In context of corona which statement is not true

(a)	Corona is voltage effect
(b)	Corona takes place on short transmission line
(c)	Corona is accompanied with power loss
(d)	Corona attenuates lightening surges

28.

Corona can be reduced by

(a)	Increasing operating voltage
(b)	Reducing the spacing between conductors
(c)	Increasing the effective conductor diameter
(d)	Any of above

29.

In humid weather, corona occurs at a voltage

(a)	Much less than needed in fair weather
(b)	Much higher than that needed in fair weather
(c)	Equal to that needed in fair weather
(d)	None of above

30.

Which of the following affects the corona least?

Showing 21 to 30 out of 47 Questions