A parallel plate capacitor has its length, width and separation doubled. It fringing effects are neglected, to keep the capacitance same, the dielectric constant must be

• halved
• kept the same
• doubled
• made 4 times

Correct Answer: halved

Explanation:

. When dimensions are changed, A become four times and d becomes twice.

Since ∈₀ is constant, ∈_r must be halved to keep C constant.