6.
N2008/Q2
Fig. 6.1 shows a wooden walking-stick that has a metal head and a rubber foot.
It balances on a pencil placed 0.50 m from its rubber foot.
metal head
0.50 m
pencil
(a) State the distance between the centre of mass of the walking-stick and the end of
the rubber foot.

Which of the following changes will increase the capacitance of a parallel-plate capacitor? (there could be more than one correct choice.) a) increase the charge on the plates b) decrease the poten5al between the plates c) increase the potential between the plates d) introduce a dielectric material between the plates e) decrease the separation between the plates