Question

If the charge on an electron is $1.6\times {10}^{-19}coulombs$, how many electrons should pass through a conductor in $1second$ to constitute $1ampere$ current?

Answer 1

Step 1- Given data

Charge on an electron $e=1.6\times {10}^{-19}C$

Current $I=1A$

Time $t=1s$

Step 2- Finding the formula for the number of electrons-

The formula for current is

$I=\frac{q}{t}...\left(1\right)$

Where $q$ is the total charge flowing through the circuit.

The formula for the total charge is

$q=ne$

Where $n$ is the number of electrons.

Substitute $ne$ for $q$ in equation $\left(1\right)$.

$$\begin{gathered} I=\frac{ne}{t} \\ n=\frac{It}{e} \end{gathered}$$

Step 3- Finding the number of electrons flowing through the circuit

Substitute the values to calculate $n$.

$$\begin{gathered} n=\frac{(1A)\times (1s)}{1.6\times {10}^{-19}C} \\ n=6.25\times {10}^{18}electrons \end{gathered}$$

Final answer- Hence, the number of elctrons flowing through the circuit is $6.25\times {10}^{18}electrons$.