# Power System Protection MCQs Part 26

Contents

## If fault occurs near the impedance relay, the VII ratio will be

If fault occurs near the impedance relay, the VII ratio will be

1. Constant for all distances
2. Higher than that of if fault occurs away from the relay
3. Lower than that of if fault occurs away from the relay
4. None of these

Correct answer: 3. Lower than that of if fault occurs away from the relay

## When a transmission line is energized, the wave that propagates on it is

When a transmission line is energized, the wave that propagates on it is

1. Current wave only
2. Voltage wave only
3. Both of above
4. Power factor wave only

Correct answer: 3. Both of above

## The reflection co-efficient of the wave of load connected to transmission line if surge impedance of the line is equal to load

The reflection co-efficient of the wave of load connected to transmission line if surge impedance of the line is equal to load

1. Infinity
2. Unity
3. Zero
4. None of these

## A thermal protection switch can protect against

A thermal protection switch can protect against

1. Over voltage
3. Short-circuit
4. Temperature

## As compared to a rewireable fuse, the HRC fuse has

As compared to a rewireable fuse, the HRC fuse has

1. High rupturing capacity
2. High speed of operation
3. No ageing effect
4. All of these

Correct answer: 4. All of these