Question

A current of $5A$ flows through a conductor. Calculate the number of electrons flowing through the conductor in $2s.$ [Take charge of electron as $1.6\times {10}^{-19}$

• A. $1.6\times {10}^{19}$
• B. $6.25\times {10}^{19}$
• C. $125\times {10}^{18}$
• D. $16\times {10}^{19}$

Answer 1

The correct option is B $6.25\times {10}^{19}$

Total charge that flows in 2s is given by

$q=It=5\times 2=10C$

Now, charge on one electron is given by $e=1.6\times {10}^{-19}C$

$N=$ number of electrons

$q=Ne$

$⟹N=\frac{q}{e}$

$⟹N=\frac{10}{1.6\times {10}^{-19}}$

$⟹N=6.25\times {10}^{19}$

Answer-(B)