Question

an air capacitor is formed by square plates of size 20cm ×20cm . If distance between the plates is 0•01cm,find the capacitance of the capacitor​

Answer 1

Answer :

Size of plates = 20cm × 20cm

Distance between plates = 0.01cm

We have to find capacitance of the capacitor $.$

$\star$ Capacitance of a parallel plate capacitor is given by

• C = ε｡A / d

ε｡ denotes permittivity of air

A denotes area of plate

d denotes distance between plate

By substituting the given values,

$\implies\tt\:C=\dfrac{(8.85\times 10^{-11})(20\:cm\times 20\:cm)}{0.01\:cm}$

• 1 cm = 0.01 m

$\implies\tt\:C=\dfrac{(8.85\times 10^{-11})(400\times 10^{-4})}{0.01\times 10^{-2}}$

$\implies\tt\:C=354\times 10^{-10}$

$\implies\bf\:C=35.4\:nF$

$\star$ Capacitance of a spherical conductor of radius R,

• C = 4πε｡R

$\star$ Capacitance of a spherical capacitor,

• C = 4πε｡ × ab/(b - a)

Here a and b are the radii of the inner and outer shells of the capacitor.