Equivalent capacitance
\(= \frac{2 \times 3}{2+3} = \frac{6}{5} \mu\)
Total charge, Q = CV = \(\frac{6}{5} \times 1000\)
= 1200 μC
Potential (V) across 2μF is
\(V = \frac{Q}{C} = \frac{1200}{2} = 600 V\)
Potential on internal plates
= 1000 - 600 = 400 V