What is the unit of electric potential difference?

An electric bulb should be connected to how much voltage line if it draws an electric current of $0.5\, A$,the resistance of the filament of that bulb being $440\, \Omega$ (in $, V$)?

Find the equivalent resistance across the two ends $A$ and $B$ of this circuit.

Derive an expression for equivalent resistance when three resistors of resistance $R_{1}, R_{2}$ and $R_{3}$ are connected in parallel.

What happens to the resistance of a conductor when its temperature is increased?

List any two factors on which the resistance of a conductor depends.