$(a)$ How is the direction of electric current related to the direction of flow of electrons in a wire?
$(b)$ Calculate the current in a circuit,if $500 \, C$ of charge passes through it in $10$ minutes.

(N/A) The direction of electric current is conventionally defined as opposite to the direction of the flow of electrons in a wire.
$(b)$ Given:
Charge $(Q) = 500 \, C$
Time $(t) = 10 \, \text{minutes} = 10 \times 60 \, \text{s} = 600 \, \text{s}$
Using the formula for electric current:
$I = \frac{Q}{t}$
$I = \frac{500 \, C}{600 \, \text{s}}$
$I = 0.833 \, \text{A}$
Therefore,the current in the circuit is approximately $0.833 \, \text{A}$.