Question

In a parallel plate capacitor, the capacitance increases from 100 F to 800 F, on introducing a dielectric medium between the plates. What is the dielectric constant of the medium?

(a) 0.125

(b) 125

(c) 80

(d) 8

This question was addressed to me in a national level competition.

My question is from Effect of Dielectric on Capacitance topic in portion Electrostatic Potential and Capacitance of Physics – Class 12

Answer 1

The correct option is (d) 8

Easy explanation: Capacitance with dielectric = 800 F

Capacitance without dielectric = 100 F

Dielectric constant = \( ( \frac {Capacitance \, with \, dielectric}{Capacitance \, without \, dielectric} ) \)

k = \(( \frac {800 F}{100 F} )\)

k = 8.

Therefore, the dielectric constant is calculated as 8.