Dielectrics question from MHT CET 2024 (9 May, Shift 1)

Answer: (a)

1. Polarisation of the dielectric weakens the field between the plates: $E = \frac{E_0}{K}$.
2. Potential difference falls to $\frac{V_0}{K}$ and capacitance rises to $KC_0$; area is unchanged.
3. So the answer is (a) to reduce the effective potential on plates.