Question

The radius of the wire in a coaxial cable is 0.65 mm and the inner radius of the coaxial conducting cylinder is 1.45 mm. Assuming that there is vacuum between the wire and the cylinder, calculate the capacitance of a 1.5 m length of the cable.

Answer 1

C = 2 x π x e x e0 x l / ln(2/1) 

e for vacuum = 0.85

e0 = 8.5x10^−12

С = (2x3.14x1.8x8.5x10−12 x 1.5)/ ln(1.45/0.65) 

    = 104  

= 104