If a current of 0.1 A flows through conductor,find the no. of electrons crossing thearea of cross-section per sec. Also find net flow of charge if this current is maintainedfor 1 hr.

As current is defined as total charge flowing per unit time. Thus it is related as:
$I=\frac{Q}{t}$
where, I = current
Q = charge
t = time
As, I = 0.1 A, t = 1 s
​Therefore,
$$\begin{gathered} I=\frac{Q}{t} \\ \Rightarrow 0.1=\frac{Q}{1} \\ \Rightarrow Q=0.1 C \end{gathered}$$
Let there be n number of electrons flowing per unit cross-section.
$$\begin{gathered} ne=Q \\ n=\frac{Q}{e}=\frac{0.1}{1.6\times {10}^{-19}}=0.0625\times {10}^{19}=6.25\times {10}^{17} \end{gathered}$$
To find the flow of net charge when the current is maintained for 1 hour.
Time, t = 1 hour = 60×60=3600 s
$$\begin{gathered} I=\frac{Q}{t} \\ \Rightarrow Q=It=0.1\times 3600=360 C \end{gathered}$$