# Basic Electrical Engineering MCQs Part 14

Basic Electrical Engineering MCQs Part 14

## If potential difference across conductor of material having resistivity ρ remains constant, then heat produced is proportional to:

If potential difference across conductor of material having resistivity ρ remains constant, then heat produced is proportional to:

1. 1/ρ
2. Ρ
3. ρ²
4. 1/√ρ

## A constant voltage is applied between two ends of uniform metallic wire. Some heat is developed. If both length and radius of wire are halved, heat developed in same duration is

A constant voltage is applied between two ends of uniform metallic wire. Some heat is developed. If both length and radius of wire are halved, heat developed in same duration is:

1. Twice
2. Same
3. Half
4. One-fourth

## The fuse wire is made of

The fuse wire is made of:

1. Copper
3. Tungsten
4. Nichrome

## Certain motor draws 20 A from 230 V source. If motor is 90 efficient, the horsepower rating is

Certain motor draws 20 A from 230 V source. If motor is 90 efficient, the horsepower rating is:

1. 3 HP
2. 6 HP
3. 12 HP
4. 20 HP

Solution:

Motor input = VI = 230 * 20 = 4600 W

————

Motor output =  η * Motor input = 0.9 * 4600 = 4140 W

———— Horsepower rating of motor = 4140/746 = 6 HP

## Which of following is immaterial for a fuse

Which of following is immaterial for a fuse:

1. Length