Consider the intermediate situation
when the conductors 1 and 2 have charges Q¢ and
–Q¢ respectively At this stage, the potential difference
V¢ between conductors 1 to 2 is Q¢/C, where C is the
capacitance of the system Next imagine that a small
charge d Q¢ is transferred from conductor 2 to 1 Work
done in this step (d W), resulting in charge Q¢ on
conductor 1 increasing to Q¢+ d Q¢, is given by
Q
W
V
Q
Q
C
δ
δ
′δ
=
=
′
′
′
(2