MCQs of Basic Principles (Power System - II - 3150911)

Power System - II (3150911) MCQs

MCQs of Basic Principles

Showing 61 to 70 out of 135 Questions

61.

A single phase transmission line of Impedance j0.8 Ω supplies a resistive load of 500 A at 300 V. The sending end power factor is

(a)	Unity
(b)	0.8 lagging
(c)	0.8 leading
(d)	0.6 lagging

62.

For AC transmission line of length not exceeding 80 km, it is usual to lump the line capacitance at

(a)	Sending end
(b)	Receiving end
(c)	Midpoint
(d)	Any convenient point

63.

If L, C and Y are inductance, capacitance and shunt admittance of a line for unit length then for length l

(a)	Shunt admittance is Yl
(b)	Inductance is L/l
(c)	Capacitance is C/l
(d)	Shunt admittance is Y/l

64.

Transmission efficiency of a line increases with

(a)	Decrease in power factor and voltage
(b)	Increase in power factor and voltage
(c)	Increase in power factor but decrease in voltage
(d)	Increase in voltage but decrease in power factor

65.

Considering two parallel short transmission lines of impedance Z_A and Z_B respectively. Current I_A and I_B are both lagging and sending end voltage is V_s. If the reactance to resistance ratio of both the impedance Z_A and Z_B are equal then total current I will be

(a)	Lagging by both I_A and I_B
(b)	Leading by both I_A and I_B
(c)	In phase with both I_A and I_B
(d)	None of above

66.

Under no load conditions the current in a transmission line is because of

(a)	Capacitance effect
(b)	Corona effect
(c)	Proximity effect
(d)	Back flow from earth

67.

Charging current in transmission line

(a)	Reduces the line losses
(b)	Increases the line losses
(c)	Will not affect the line losses
(d)	Unpredictable

68.

Which of the following statements are correct

(a)	Flow of unduly heavy current is Ferranti effect
(b)	Ferranti effect occurs under unloaded condition of line
(c)	Rise in receiving end voltage is Ferranti effect
(d)	Both (b) and (c) combined is Ferranti effect

69.

The phenomenon of rise in receiving end voltage of the open circuited or lightly loaded line is called

(a)	Proximity effect
(b)	Skin effect
(c)	Ferranti effect
(d)	Seebeck effect

70.

For a long distance HV transmission line the receiving end voltage under on loaded condition is

(a)	Much lower than sending end voltage
(b)	Lower than sending end voltage
(c)	Equal to sending end voltage
(d)	Higher than sending end voltage

Showing 61 to 70 out of 135 Questions