(a)[1]
State one material that acts as an electrical insulator.
(b)[2]
On Fig. 7.1, sketch the charge distribution on P.
(c(i))[1]
On Fig. 7.2, show how the charges are arranged on P with the earth wire connected.
(c(ii)-1)[1]
State what happens to the charges on P if the positively charged rod is removed while the earth wire is still connected to P.
(c(ii)-2)[1]
State what happens to the charges on P after the earth wire is disconnected from P.