The capacitance of a capacitor, when a dielectric is introduced in the space between plates
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → increases
A dielectric placed between the plates gets polarised. The charges induced on its faces are opposite to those on the plates, so they reduce the electric field between the plates. For the same charge Q, the potential difference V falls, so the capacitance \( C = Q/V \) rises.
\( \displaystyle C = K C_0, \quad K \gt 1 \)
So the capacitance increases by the factor K, the dielectric constant of the material.
NCERT (2026-27):
Effect of Dielectric on Capacitance – “… Thus, the dielectric constant of a substance is the factor (>1) by which the capacitance increases from its vacuum value, when the dielectric is inserted fully between the plates of a capacitor.”