Question

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. $2C$

Answer 1

Answer: (B)

$4C$

Answer 2

$C = \frac{K\varepsilon_{0}A}{d};$ ∴ $\frac{C_{1}}{C_{2}} = \frac{K_{1}}{K_{2}}$ ⇒ $\frac{C}{C_{2}} = \frac{5}{20}$ ⇒ C₂ = 4C