(a(i))[1]
On Fig. 6.1, add one voltmeter and one ammeter in positions that will allow the resistance of X to be determined.
(a(ii))[2]
Explain how X and R operate as a variable potential divider.
(b(i))[1]
State the relationship between the resistance of the wire and the length of the wire.
(b(ii))[3]
Calculate the current in a $90\,\text{cm}$ length of the wire when the potential difference (p.d.) across it is $9.0\,\text{V}$. Show your working.
(b(iii))[2]
The p.d. across the wire used for resistor X is held constant for every resistance measurement. Describe the relationship between the current in the wire and the wire length.
(c)[1]
State how the resistance of a wire depends on the wire’s cross-sectional area.