MCQs of Transients in Power Systems (Power System - II - 3150911)

Power System - II (3150911) MCQs

MCQs of Transients in Power Systems

Showing 51 to 60 out of 106 Questions

51.

The over voltage surges in power system may be caused by

(a)	Lightening
(b)	Resonance
(c)	Switching
(d)	All of above

52.

Earthed lightning rods are provided

(a)	About the overhead lines
(b)	Above all tall buildings
(c)	At the substation
(d)	Near motor and generator terminals

53.

Requirements of protection of power station buildings against direct strokes are

(a)	Interception
(b)	Conduction
(c)	Dissipation
(d)	All of above

54.

The protection against direct lightning strokes and high voltage steep waves is provided by

(a)	Ground wires
(b)	Lightning arresters
(c)	Lightning arresters and ground wires
(d)	Earthing of neutral

55.

Which of the following factors should be considered in the design of transmission lines against lightning with ground wire?

(a)	Mechanical strength of ground wire
(b)	Clearance between the line conductor and ground wire
(c)	Clearance between line conductor and earth
(d)	All of above

56.

Protection of rotating machines against lightning surges is carried out by

(a)	Lightning arresters
(b)	Capacitor
(c)	Lightning arresters and capacitor both
(d)	Lightning conductor in arresters

57.

Consider the following statements. To provide reliable protection for distribution transformer against over voltage is using lightning arresters, it is essential that
1. Lead resistance is high
2. Distance between transformer and arrester is small
3. Transformer and arrester have a common interconnecting ground
4. Spark over voltage of the arrester is greater than the residual voltage

(a)	1, 3 and 4 are correct
(b)	2 and 3 are correct
(c)	2, 3 and 4 are correct
(d)	1 and 4 are correct

58.

Impulse ratio of insulator and lightning arresters should be

(a)	Both low
(b)	High and low respectively
(c)	Low and high respectively
(d)	Both high

59.

Lightning arresters are used in power systems to protect electrical equipment against

(a)	Direct stroke of lightning
(b)	Over voltage due to indirect lightning stroke
(c)	Power frequency over voltage
(d)	Over current due to lightning

60.

The impulse ratio of rod gap is

(a)	Unity
(b)	Between 1.2 and 1.5
(c)	Between 2 and 2.2
(d)	None of above

Showing 51 to 60 out of 106 Questions