Question

Capacitance of parallel plate capacitor derivation

Answer 1

Answer:

A parallel plate capacitor consist of two large plane parallel conducting plates separated by a small distance .

The electric field intensity between two closely spaced parallel plates in vacuum is given by,

E=¶/£

where , ¶=surface density on either plate.

¶=Q/A

Q=charge on either plate

A=area of each plate

E=¶/£=1/£ Q/A.......1

Relation between electric field & potential difference is,

E=V/D........2

from 1 & 2,

Q/£A=V/d

Q/V=£A/d

from the definition of capacitance, C=Q/V

C = £A/d

if the space between the plates is filled with a medium of dielectric constant 'k' then ,

C=K£A/d