Question

A current of $4.8A$ is flowing in a conductor. The number of electrons passing per second through the conductor will be :

• A. $3\times {10}^{20}$
• B. $76.8\times {10}^{20}$
• C. $7.68\times {10}^{-19}$
• D. $3\times {10}^{19}$

Answer 1

The correct option is D $3\times {10}^{19}$

Given,
$e=1.6\times {10}^{-19}C$, $I=4.8A$
Let number of electrons per second be $n$.
The current is defined as rate of flow of charge,
$I=\frac{q}{t}$
Hence
$q=n\times e$
Therefore, $I=\frac{n\times e}{t}$
Substituting values,
4.8 $=n\times 1.6\times {10}^{-19}$
Hence, $n=\frac{4.8}{1.6\times {10}^{-19}}=3\times {10}^{19}$ electrons per second.