Question

If the electronic charge is $1.6\times {10}^{-19}$ C, then the number of electrons passing through a section of wire per second, when the wire carries a current of 2A, is

• A. $1.25\times {10}^{17}$
• B. $1.6\times {10}^{17}$
• C. $1.25\times {10}^{19}$
• D. $1.6\times {10}^{19}$

Answer 1

The correct option is C $1.25\times {10}^{19}$

Given : $e=1.6\times {10}^{-19}$ C $I=2$ A $t=1$ s

Using $I=\frac{ne}{t}$

$\therefore$ Number of electrons $n=\frac{It}{e}=\frac{2\times 1}{1.6\times {10}^{-19}}=1.25\times {10}^{19}$ electrons