76 Aptitude Test Problems in PhysicsDetermine the potential cp 2 acquired by
the sphere after it has been connected for ashort time to the shell by a conductor.
Fig. 773.10. A very small earthed conducting sphere
is at a distance a from a point charge q l
and at a distance b from a point charge
q 2 (a < b). At a certain instant, the sphere
starts expanding so that its radius grows
according to the law R = vt.
Determine the time dependence I (t) of
the current in the earthing conductor, assum-
ing that the point charges and the centre
of the sphere are at rest, and in due time
the initial point charges get into the expand-
ing sphere without touching it (through
small holes).
3.H. Three uncharged capacitors of capac-
itance C1, C2, and C3 are connected as
shown in Fig. 78 to one another and to
points A, B, and D at potentials TA, T B, and
(PD.
Determine the potential To at point 0.