# Fuses - MCQs with answers

## Fuses - MCQs with answers

Q1. Which among these are the main characteristics of a fuse element?

a. Low melting point
b. High conductivity
c. Least deterioration due to oxidation
d. All of the above

ANSWER: d. All of the above

Q2. Which among the following statement is true related to fuse?

a. Greater the current smaller is the time taken by the fuse to blow out.
b. Greater the current greater is the time taken by the fuse to blow out.
c. The current is directly proportion to the blow out time of fuse.
d. Is dependent on the temperature and atmospheric conditions.

ANSWER: a. Greater the current smaller is the time taken by the fuse to blow out.

Q3. Which among these is the least expensive protection for over current in low voltage system?

a. Rewirable fuse.
b. Isolator.
c. Circuit breaker.
d. Air breaker switch.

Q4. For a current upto 10A which material is used as the fusing element?

a. Copper
b. Silver
c. Alloy of lead and tin
d. Zinc

Q5. What is the relation between the fusing current and the diameter of the wire?

a. I = k d3
b. I = k d3/2
c. I = k d2
d. I = k d2/3

ANSWER: b. I = k d3/2

Q6. What is fusing factor?

a. The ratio of current rating of the fuse to the minimum fusing current.
b. The ratio of minimum fusing current to the current rating of the fuse.
c. The ratio of maximum fusing current to the current rating of the fuse.
d. The ratio of minimum fusing current to the voltage rating of the fuse

ANSWER: b. The ratio of minimum fusing current to the current rating of the fuse.

Q7. What should be the value of fusing factor?

a. Equal to zero
b. Equal to one
c. Less than one
d. More than one

Q8. What is the maximum current upto which fuses can be used?

a. 25 A
b. 50 A
c. 75 A
d. 100 A

Q9. What is the typical value of the pre arcing time?

a. 0.1
b. 0.01
c. 0.001
d. 0.0001

Q10. A fuse wire of circular cross section has a radius of 0.8mm. The wire blows off at a current of 9A. What will be the radius of the wire that will blow off at a current of 1A?

a. 0.2 mm
b. 0.18 mm
c. 0.28 mm
d. 0.3 mm