41
Transmission voltage of ll kV is normally used for distances upto
Answer: 20—25 km
Questions
43
Which of the following bus-bar schemes has the lowest cost ?
Answer: Single bus-bar scheme
44
By which of the following methods string efficiency can be improved ?
Answer: Any of the above
45
By which of the following a bus-bar is rated ?
Answer: Current, voltage, frequency and short time current
46
For which of the following equipment current rating is not necessary ?
Answer: Isolators
47
jCorona usually occurs when the electrostatic stress in air around the conductor exceeds
Answer: 30 kV (maximum value)/cm
48
The current drawn by the line due to corona losses is
Answer: non-sinusoidal
49
Pin type insulators are generally not used for voltages beyond
Answer: 33 kV
51
For transmission of power over a distance of 200 km, the transmission voltage should be
Answer: 132 kV
52
Which of the following equipment, for regulating the voltage in distribution feeder, will be most economical ?
Answer: Booster transformer
53
In a tap changing transformer, the tappings are provided on
Answer: high voltage winding
54
On which of the following factors skin effect depends ?
Answer: All of the above
55
For transmission of power over a distance of 500 km, the transmission voltage should be in the range
Answer: 150 to 220 kV
56
Electro-mechanical voltage regulators are generally used in
Answer: Generators
57
When a conductor carries more current on the surface as compared to core, it is due to
Answer: skin effect
59
When a live conductor of public electric supply breaks down and touches the earth which of the following will happen ?
Answer: Current will flow to earth
60
The voltage regulation in magnetic amplifier type voltage regulator is effected by
Answer: varying the reactance
