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

Answer: (B)

Step 1: Quantization of charge
We know that charge on a body is quantized and can be given as:
$ q = Ne $
where, $N$ is number of electrons present on the body, $e$ is the
charge on an electron
Step 2: Substitute the values
From equation (1)
$-1 \times 10^{-9} C =-1.6 \times 10^{-19} C \times N $ $N =\frac{10^{-9}}{1.6 \times 10^{-19}}=6.25 \times 10^9 \text { electrons. }$