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

where Q= total charge and e=e is the charge per electron

Answer 2

Answer:

A current of 50mA flows for 0.5 hours through an electric circuit. calculate the no of electrons that will drift in the circuit will be $5.6\times 10^{20}$ electrons

Explanation:

• In the question, it is given that,

      Time,  $0.5h= 0.5\times 60\times 60 s= 1800s$

      Current,  $I = 50mA = 50\times 10^{-3} A$  

      Charge of 1 electron,  $e = 1.6\times 10^{-19}C$

• Consider a conductor of current flowing I, Q be the total charge of electrons and t be the time.

       Then, we have the expression for current as,

       $I=\frac{Q}{t}$  

      That is,

       $Q = It$            ...(1)

       Here Q is given by the expression,

       $Q = ne$  

       Or

       $n= \frac{Q}{e}$             ...(2)

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

• Substitute the values given in the question into equation (1)

      $Q = (50\times 10^{-3}\times 1800 )= 90C$

      Then equation(2) becomes,

      $n= \frac{90}{1.6\times 10^-19}= 5.6\times 10^{20}$ electrons