What happens to the capacitance of an isolated parallel-plate capacitor if a dielectric slab with dielectric constant κ = 4 is inserted between the plates?
Answer and explanation
Correct answer: A. It increases by a factor of 4
- Step 1: Recall the formula for capacitance with a dielectric material: .
- Step 2: Since , the capacitance becomes four times the original vacuum capacitance .
Answer
It increases by a factor of 4.
Why not the others: Capacitance never decreases when a dielectric is added; remaining unchanged ignores permittivity; 16 squares the dielectric constant.
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