Question

Find out the correct expression of the capacitance of a parallel plate capacitor where ‘A’ is the area of the plates, ‘d’ is the distance between the plates and ‘ε0’is the permittivity of the medium.

(a) \(\frac {A\varepsilon_0}{d}\)

(b) \(\frac {Ad}{\varepsilon_0}\)

(c) \(\frac {d\varepsilon_0}{A}\)

(d) Aε0d

I got this question in semester exam.

My question is based upon Parallel Plate Capacitor in chapter Electrostatic Potential and Capacitance of Physics – Class 12

Answer 1

Right answer is (a) \(\frac {A\varepsilon_0}{d}\)

Easy explanation: The capacitance of a parallel plate capacitor is directly proportional to the area of the plates and permittivity of the medium between the plates. It is indirectly proportional to the distance between the plates.

C = \(\frac {Q}{V} = [ \frac {\sigma A}{(\frac {\sigma d}{\varepsilon_0})} ] = \frac {A\varepsilon_0}{d}\).