Question

How many electrons flow through a battery that delivers a current of 4.0 A for 12 s?a- 4.0 × 1020b- 3.0 × 1020c- 4.8 × 1015d- 2.2 × 1020e- 6.4 × 1018

Answer 1

Given:

The current flowing in the circuit is I = 4 A

The time duration is t = 12 s

Required: Number of electrons flowing through the circuit.

Explanation:

First, we need to calculate the charge flowing in the circuit.

The charge flowing in the circuit can be calculated by the formula

$\begin{gathered} I=\frac{q}{t} \\ q=I\times t \end{gathered}$

On substituting the values, the charge will be

$\begin{gathered} q=4\times12 \\ =48\text{ C} \end{gathered}$

The number of electrons can be calculated by the formula

$\begin{gathered} q=ne \\ n=\frac{q}{e} \end{gathered}$

Here n is the number of electrons

e is the charge on one electron whose value is

$e=1.6\times10^{-19}\text{ C}$

On substituting the values, the number of electrons will be

$\begin{gathered} n=\frac{48}{1.6\times10^{-19}} \\ =3\times10^{20}\text{ } \end{gathered}$

Final Answer: There are 3e20 electrons flowing through the battery.