How much work is done in moving a charge of $2 \, C$ across two points having a potential difference of $12 \, V$ (in $, J$)?

$A$ bulb gets dimmer for a moment when a geyser,connected across the same source,is switched on. Why?

List in a tabular form two differences between a voltmeter and an ammeter.

The equivalent resistance between points $A$ and $B$ in the following electric circuit is:

Two electric circuits $I$ and $II$ are shown in the figure.
$(i)$ Which of the two circuits has more resistance?
$(ii)$ Through which circuit does more current pass?
$(iii)$ In which circuit is the potential difference across each resistor equal?

Explain the terms potential and potential difference. Give their $SI$ units.