Making a parallel-plate capacitor?

Question

You have two plates of copper, a sheet of mica (thickness = 0.10 mm, k = 5.4), a sheet of glass (thickness = 2.0 mm, k = 7.0), and a slab of paraffin (thickness = 1.0 cm, k = 2.0). To make a parallel-plate capacitor with the largest C, which sheet should you place between the copper plates?

Answer 1

Well, C is linearly proportional to k, and inversely proportional to d. So, you want to maximize the ratio k / d.

Converting everything to cm, you see that mica is 0.01cm, glass is 0.2cm, and paraffin is 1.0cm. You can easily se that mica will produce the largest capacitance.

Answer 2

Hi. Just multiply. Mica is a good bet.