Question

Number of electrons present in a negative charge of $8$ coulomb is?

• A. $5\times {10}^{19}$
• B. $2.5\times {10}^{19}$
• C. $12.8\times {10}^{19}$
• D. $1.6\times {10}^{19}$

Answer 1

The correct option is A $5\times {10}^{19}$

Magnitude of charge $Q=8C$
Magnitude of one electronic charge $e=1.6\times {10}^{-19}C$
Let the number of electron present be $N$.
Thus, number of electrons $N=\frac{Q}{e}$
$⟹N=\frac{8}{1.6\times {10}^{-19}}=5\times {10}^{19}$ electrons