Question

A parallel plate capacitor of capacitance 100 pF is to be constructed by using paper sheets of 1 mm thickness as dielectric. If the dielectric con stant of paper is 4, the number of circular metal foils of diameter 2 cm each requied for the pur pose is​

Answer 1

Answer:

The answer will be 10

Explanation:

According to the problem the capacitance of the parallel plate is 100 pF

The thickness of the sheets is given as 1 mm

The dielectric constant of the paper is given

Now let the number of foils required is p and it will need (p-1) capacitors

Now let the dielectric constant is k

Therefore the capacitance is given by

c = ke0(p-1)A/d

=> (p-1) = cd/ke0A = cd/k x 4πe0A = 4π/πr^2 =  4cd/ k x 4πe0r^2

                  = 4 x 10^(-1) x 1 x 10^(-3) x 9 x 10^9/4(1.0 x 10^(-2))^2 = 9

p = 10