(a(i))[1]
State the name of the device used to measure potential difference (p.d.) in an electric circuit.
(a(ii))[1]
State the unit used for the electromotive force (e.m.f.) of a battery.
(b(i))[3]
Calculate the wire's resistance.
(b(ii))[2]
State two ways of choosing a wire with a higher resistance by comparing its length and thickness with the wire in (b)(i).