# Electrical Power Transmission MCQs Part 16

Electrical Power Transmission MCQs Part 16

## Potential across the various discs of suspension string is different. This is primarily due to

Potential across the various discs of suspension string is different. This is primarily due to:

1. Self-capacitance
2. Shunt capacitance
3. Both of these
4. None of these

Also see: String efficiency formula

## If safety factor is doubled, sag of line will

If safety factor is doubled, sag of line will:

1. Increase
2. Decrease
3. Remain unchanged
4. None of the above

Explanation:

The formula for allowable tension (T) is: T = Ultimate strength/Safety factor

While Sag has the formula: S = (wl²)/8T = {(wl²)/8 } * {Safety Factor/Ultimate strength}

Since both are directly related to each other, doubling safety factor increases sag

## Shunt capacitance in string of suspension insulators can be decreased using

Shunt capacitance in string of suspension insulators can be decreased using:

1. Shorter cross-arms
2. Longer cross-arms
3. Longer spans
4. None of these

Explanation: In order to reduce shunt capacitance, distance of conductor from tower must be increased. In other terms/words, the longer cross-arms should be used.

## If spacing between conductors increases, the corona effect

If spacing between conductors increases, the corona effect:

1. Increases
2. Decreases
3. Remains unchanged
4. None of these

Explanation: If spacing between conductors is large compared to their diameters, the electrostatic stress at conductor surface is decreases. As a result of this the corona effect decreases.

## Power loss in an overhead transmission line mainly occurs due to

Power loss in an overhead transmission line mainly occurs due to:

1. Resistance of the line
2. Capacitance of the line
3. Inductance of the line
4. None of these

Correct answer: 1. Resistance of the line

Explanation: The line resistance is the major factor that is responsible for power loss in an overhead transmission line.

See complete list of Electric Power Transmission MCQs