Question

The number of electrons flowing in 1 second when $1A$ current flows through a wire is:

[Take charge on one electron $=1.6\times {10}^{-19}C$]

• A. $7\times {10}^{18}$
• B. $6.5\times {10}^{18}$
• C. $6\times {10}^{18}$
• D. $6.25\times {10}^{18}$

Answer 1

The correct option is D

$6.25\times {10}^{18}$

Given: Current $I=1A$

Time $t=1s$

Charge on one electron, $Q=1.6\times {10}^{-19}C$

Let the number of electrons be $n$

We know that $I=\frac{Q}{t}$ and $Q=n\times \text{e}$

$\Rightarrow$ $I=\frac{n\times \text{e}}{t}$

On substituting the values, $1=\frac{n\times 1.6\times {10}^{-19}}{1}$

$\Rightarrow n=\frac{1}{1.6\times {10}^{-19}}=6.25\times {10}^{18}$

Therefore, the number of electrons flowing in 1 second when $1A$ current flows through a wire is $6.25\times {10}^{18}$.