Q. The capacity of a condenser in which a dielectric of dielectric constant 5 has been used, is $C.$ If the dielectric is replaced by another with dielectric constant 20, the capacity will become
A) $\frac{C}{4}$
B) $4C$
C) $\frac{C}{2}$
D) $2C$
Explanation
(b) $C = \frac{K\varepsilon_{0}A}{d};\ \therefore\frac{C_{1}}{C_{2}} = \frac{K_{1}}{K_{2}} \Rightarrow \frac{C}{C_{2}} = \frac{5}{20} \Rightarrow C_{2} = 4C$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.