Physics · Oct / Nov 2016 · Paper 11 · Question 33

A coil P of $N$ turns is made from a length $L$ of wire. The coil carries a current $I$ when between two magnetic poles. [diagram of coil between N-pole and S-pole] A similar coil Q of $2N$ turns is made from a length $2L$ of identical wire. It also carries a current $I$ when between the two magnetic poles. Which coil has the greater resistance and which coil experiences the greater turning effect?

1. Agreater resistance: P; greater turning effect: P
2. Bgreater resistance: P; greater turning effect: Q
3. Cgreater resistance: Q; greater turning effect: P
4. Dgreater resistance: Q; greater turning effect: Q

As printed in the paper