The charge on an electron is $1.6\times10^{-19}$ C. Find the number of electrons that will flow per second to constitute a current of 2A?

Given: charge on an electron is $1.6\times10^{-19}$ C

To find:  the number of electrons that will flow per second to constitute a current of 2A

Solution:

The current is defined as the rate of flow of charged particles.

So, $\mathrm{i}=\frac{\mathrm{Q}}{\mathrm{t}}$

Hence the charge flown is, $\mathrm{Q}=\mathrm{i} \mathrm{t}$

So $\mathrm{Q}=2 \times 1=2 \mathrm{C}$

If $\mathrm{N}$ is number of electrons passing and $\mathrm{e}$ is the electronic charge of value $1.6 \times 10^{-19}$

The charge $\mathrm{Q}$ is due to electrons, therefore, $\mathrm{Q}=\mathrm{N} \times \mathrm{e}$

Here $\mathrm{Q}=2 \mathrm{C}$

Then, $\mathrm{N}=\frac{\mathrm{Q}}{\mathrm{e}}=\frac{2}{1.6 \times 10^{-19}}$

$=1.25 \times 10^{19}$ electrons

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Updated on: 10-Oct-2022

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