Question

a current of 50mA flows for 0.5 hours through an electric circuit. calculate the no of electrons which will drift in the circuit

Answer 1

3.2 * 10^18 electrons

Answer 2

Answer:

A current of 50mA flows for 0.5 hours through an electric circuit, the no of electrons that will drift in the circuit is, $5.6\times 10^{17}$ electrons

Explanation:

• Let I be the current flowing through an electrical circuit t be the time of flow and Q be the total charge.  

        We have the expression for the total charge as,

        $Q = It$     ...(1)

       Also, we have another expression for Q as,

       $Q =ne$    ...(2)

       Where n is the number of electrons in the circuit and e is the charge of one electron.

      Equating equations(1) and (2)

      $It = ne$

      or

      $n = \frac{It}{e}$     ...(3)

• From the question,

       $I = 50mA = 50\times 10^{-6} A$

       $t = 0.5h = 0.5\times 60 \times 60 = 1800s$

       we know,

       $e = 1.6\times 10^{-19} C$

       Substituting these values into equation (3)

       $n = \frac{50\times 10^{-6} \times 1800}{1.6\times 10^{-19}} = 5.6\times 10^{17}$ electrons