Question

When the starter motor of a car is switched on for 0.8s, 24C of charge passes through the coil of the motor. The current (A) in the coil is
A. 30
B. 10
C. 25
D. 32

Answer 1

Hint: In order to solve this question, we have to use the current formula directly and we know that current is the charges flowing per unit time. Dividing the charge and time we can find the current flowing through the coil.

Step by step answer: Charge quantization is the principle that the charge of any object is an integer multiple of the elementary charge. Also we know that current is the charges flowing per unit time. Hence the current formula.

Given: Charge (Q) =24C
            Time=0.8s
so to get the answer by using the formula is $\dfrac{Q}{t}$
so,
we have the current formula
 I=$\dfrac{Q}{t}$

I= 24/0.8

$\Rightarrow$ I =30A

Therefore, the current in the coil is 30A.
Hence the correct option is A

Note: Students must not get confused with the formula of Q=ne but this formula we are using for calculating the number of electrons and charge. Hence we use the current formula. The quantization of an object's charge can be exactly 0 e, or exactly 1 e, −1 e, 2 e, etc., but not, say or −3.