$(a)$ Define the term 'volt'.
$(b)$ State the relation between work,charge,and potential difference for an electric circuit. Calculate the potential difference between the two terminals of a battery,if $100 \ J$ of work is required to transfer $20 \ C$ of charge from one terminal of the battery to the other.

(N/A) One volt is defined as the potential difference between two points in a current-carrying conductor when $1 \ J$ of work is done to move a charge of $1 \ C$ from one point to the other.
$(b)$ The relation between potential difference $(V)$,work $(W)$,and charge $(Q)$ is given by the formula: $V = W / Q$.
Given:
Work $(W)$ = $100 \ J$
Charge $(Q)$ = $20 \ C$
Using the formula $V = W / Q$:
$V = 100 \ J / 20 \ C = 5 \ V$.
Therefore,the potential difference between the two terminals of the battery is $5 \ V$.