Question

Suppose, one wishes to construct a 1⋅0 farad capacitor using circular discs. If the separation between the discs be kept at 1⋅0 mm, what would be the radius of the discs?

Answer 1

The radius of the discs is equal to 6Km

Explanation:

• From the given considering the image as shown below
• Where above placed are imagined as two discs and the distance between the two discs are 1mm
• We know that area of the disc is πr2
• Given, capacitance is equal to the 1 farad

Distance D = 1 mm

= 1 $\times$ 10-3

We know Capacitance ( C )= €A/d

• Where € = dielectric constant of the capacitor
• A= Area of the plates
• d= distance between the plates

Substituting the values =>

1= 8.853 $\times$ 10-12 $\times$ πr2/1 $\times$ 10-3

=By solving the equation after substituting the value of π

We get r2= 109/27.784

=5998.6m

We can re-write the above value in cm = 6 Km  

Therefore, the radius of the discs is equal to 6Km.