Question

The plates on a capacitor have a radius of 1.5 mm and are separated by a distance of 0.43 mm. The space between the plates is filled with a dielectric that has a dielectric constant of 3.8.
What is the capacitance of this capacitor?

1) 5.5 × 10–13 F
2) 1.4 × 10–13 F
3) 5.5 × 10–10 F
4) 1.4 × 10–10 F

Answer 1

So, C = kE°A/d

putting the values,

C
= 3.8 × 8.85×10^(-12) × 3.14×1.5×1.5 × 10^(-6)/0.43 × 10^(-3)

so, 1.02 × 10^(-13)

so the most appropriate answer is 2 ...that is
1.4 × 10^(-13) ....answer !!