Question

A car headlamp of 48 W works on the car battery of 12 V. The correct fuse for the circuit of this car headlamp will be :
A. 5A
B. 2A
C. 3A
D. 15A

Answer 1

Hint: We at first need to read the question thoroughly and need to find what actually the question wants us to answer, we need to extract the values from the question that are given in the question and then find the required result. Always write the formula of the fuse rating and then solve it.

Complete step by step answer:
First, we need to look at the values that are supplied to us in the question.
The power of the car headlamp is 48W.
The supply given from the car battery is 12V.
So, according to the question we need to find the current fuse rating for the fuse of the circuit.
There are two types of rating one is the current rating another one is voltage rating we have to find the current fuse rating for the fuse.
We know that the formula for fuse rating is,
\[Fuse\text{ }rating=\dfrac{Power}{Supply\text{ }Voltage}\times 1.25A\].
\[Fuse\text{ }rating=\dfrac{48}{12}\times 1.25A\],

So on solving the above equation we get, 5 A as the current fuse rating of the circuit.

So, the correct answer is “Option A”.

Note: Before finding the current fuse rating, we need to know that what actually current fuse rating is, it is actually the maximum amount of current that a fuse will carry for an indefinite period that too without too much deterioration of the fuse element. We are finding the current fuse rating of the circuit as in the options we will see that only values in amperes are given. Moreover in the question it is easily understandable by seeing the values that only the current rating can be derived easily. So, that is the reason why we need to find the value in ampere.