Question

Any given statement in Column-I can have correct matching with ONE OR MORE statement(s) in Column-II.
Column-I gives certain situations in which capacitance of a capacitor is changed by different means.Column-II gives resulting effect under different conditions. Match the statements in column-I with the corresponding statements in column-II

Answer 1

Pulling the plates apart when charge is constant,
1. $E=\frac{Q}{A{ϵ}_0}orE=\frac{V}{d}$
for Q = const.E = const. If V = const. and d increases. Hence, E decreases (4, 5)
2. Potential energy increases because $E=Q^2/2C$ and capacitance is decreasing due to increasing distance.
Pulling the plates apart when potential is constant,
1. Electric field intensity decreases because $Ed=V$ and distance is increasing.
2. Potential energy also decreases because $E=1/2\times C{V}^2$ and capacitance is decreasing.
Introducing a dielectric always increases the capacitance. So potential energy decreases when charge is constant and increases when potential is constant.