JEE Physics · Hard

Capacitance: Dielectric Slab Partially Inserted MCQ

Solve this quality-checked JEE multiple-choice question, then review the correct answer and explanation.

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Dielectric Slab Partially InsertedHardQuestion 31552

Question

A dielectric slab of thickness t (< d) with K is inserted in a parallel-plate capacitor (plate area A, separation d). Capacitance becomes:
  1. A
    ε₀A/(d−t+t/K)
    Correct
  2. B
    ε₀KA/(d−t)
  3. C
    ε₀A/(d+t(K−1))
  4. D
    ε₀KA/d

Correct answer

ε₀A/(d−t+t/K)

Explanation

The two air gaps (d−t) and dielectric (t) act as series capacitors. C = ε₀A/(d−t+t/K).