Question

If a charge on the body is -1 nC, then how many electrons are present on the body?

• A. $1.6\times {10}^{19}$
• B. $6.25\times {10}^9$
• C. $6.25\times {10}^{27}$
• D. $6.25\times {10}^{28}$

Answer 1

The correct option is B $6.25\times {10}^9$

$\text{Step 1: Quantization of charge}$

We know that charge on a body is quantized and can be given as:

$q=Ne$ $....\left(1\right)$

where, $N$ is number of electrons present on the body, $e$ is the charge on an electron

$\text{Step 2: Substitute the values}$

From equation $\left(1\right)$

$-1\times {10}^{-9}C=-1.6\times {10}^{-19}C\times N$

$N=\frac{{10}^{-9}}{1.6\times {10}^{-19}}=6.25\times {10}^{9}electrons.$

Hence, Option(B) is correct.