Question

A current of 150 milli ampere flows through the circuit for 2 minutes find the amount of charge and no. of electrons.

Answer 1

I=150 ma = 150 x 10 to the power -3 A 
t= 120s 
 q=i/t
 q= 150/ 1000x 120
 q= 0.00125 C

Answer 2

Given that,

Current, I = 150 mA

Time, t = 2 minutes

To find,

The amount of charge and no. of electrons.

Solution,

We know that, electric current is given by :

$I=\dfrac{q}{t}$

q is amount of charge

$q=It\\\\q=150\times 10^{-3}\times 2\times 60\\\\q=18\ C$

Let there are n numbers of electrons. So,

q = ne

$n=\dfrac{q}{e}\\\\n=\dfrac{18}{1.6\times 10^{-19}}\\\\n=1.125\times 10^{20}$

Hence, the amount of charge is 18 C and there are $1.125\times 10^{20}$ electrons.