Electrical Engineering MCQs on Power Transmission MCQs Part 26
Contents
- 1 Certain string of suspension insulator comprises of three discs. If disc nearest to conductor flashes over (breaks down), which of following is correct
- 2 With occurrence of breakdown of disc nearest to conductor entire voltage across string is applied to the remaining two discs. As a result of this voltage across these exceed the flash-over voltage and remaining two discs also break down.
- 3 If lagging power factor of load decreases, the line losses will
- 4 Most common type of conductor used for overhead transmission lines is
- 5 The phenomenon of rise in voltage at the receiving end of the open-circuited or lightly loaded transmission line is termed as
Certain string of suspension insulator comprises of three discs. If disc nearest to conductor flashes over (breaks down), which of following is correct
Certain string of suspension insulator comprises of three discs. If disc nearest to conductor flashes over (breaks down), which of following is correct:
- Remaining discs will remain safe
- Remaining discs will also flash-over
- Only top disc will flash-over
- None of these
Correct answer: 2. Remaining discs will also flash-over
Explanation:
With occurrence of breakdown of disc nearest to conductor entire voltage across string is applied to the remaining two discs. As a result of this voltage across these exceed the flash-over voltage and remaining two discs also break down.
Which of following is correct regarding corona effect
Which of following is correct regarding corona effect:
- It causes power loss in the line
- It produce radio frequency waves
- It causes interference in radio communication
- All of these
Correct answer: 4. All of these
If lagging power factor of load decreases, the line losses will
If lagging power factor of load decreases, the line losses will:
- Increase
- Decrease
- Remain the same
- None of these
Correct answer: 1. Increase
Most common type of conductor used for overhead transmission lines is
Most common type of conductor used for overhead transmission lines is:
- All aluminum conductor
- ACSR conductor
- Copper conductor
- None of these
Correct answer: 2. ACSR conductor
Explanation: In terms of cost, conductivity, tensile strength, weight aluminum is preferable over the copper as transmission line conductor, however it has low tensile strength.
In order to overcome this, aluminum conductor is reinforced with a core of galvanized steel wires. The resultant being obtained is a composite conductor that is identified as steel cored aluminum and is abbreviated as ACSR or Aluminum conductor steel reinforced.
The phenomenon of rise in voltage at the receiving end of the open-circuited or lightly loaded transmission line is termed as
The phenomenon of rise in voltage at the receiving end of the open-circuited or lightly loaded transmission line is termed as:
- Ferranti Effect
- Ohm’s Effect
- Skin Effect
- Corona Effect
Correct answer: 1. Ferranti Effect