Question

A cylindrical capacitor consists of a solid inner conducting core with radius 0.300 cm , surrounded by an outer hollow conducting tube. The two conductors are separated by air, and the length of the cylinder is 11.5 cm . The capacitance is 39.0 pF .

a)Calculate the outer radius of the hollow tube.

b)When the capacitor is charged to 150 V , what is the charge per unit length ? on the capacitor?

Answer 1

Solution

Radius of inner conducting core

Radius of outer conducting tube

Length of the cylinder is

Capacitance of the capacitor

Dielectric constant of air

(a) Capacitance for cylindrical capacitor is given by,

  

    

  

The outer radius of the hollow tube = 0.3534 cm

(b) Capacitance of the capacitor is given by,

  

Charge per unit length is given by,

     

Therefore, charge per unit length on the capacitor.