Without dielectric, capacitance will be C=dAϵ0.
Therefore, charge on it, Q=dAϵ0V
Now, with dielectric capacitance will be C′=d−t+KtAϵ0.
Hence, charge on it will be Q′=d−t+KtAϵ0V
Given:
d−t+KtAϵ0V=(1.25)dAϵ0V
⇒1.25(3+K2)=5
⇒K=2
JEE Main 2024 — Physics Electromagnetism
A parallel plate capacitor with plate separation 5mm is charged up by a battery. It is found that on introducing a dielectric sheet of thickness 2mm, while keeping the battery connections intact, the capacitor draws 25 more charge from the battery than before. The dielectric constant of the sheet is ____.
Held on 31 Jan 2024 · Verified 6 Jul 2026.
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