Get Answers to all your Questions

header-bg qa

2.29        A spherical capacitor consists of two concentric spherical conductors, held in position by suitable insulating supports figure. Show that the capacitance of a spherical capacitor is given by C = \frac{4\pi \epsilon_{0}r_{1}r_{2}}{r_{1}-r_{2}} where r1 and r2 are the radii of outer and inner spheres, respectively.

            

Answers (1)

best_answer

Given

the radius of the outer shell = r_1

the radius of the inner shell = r_2

Charge on the Inner surface of the outer shell =  Q

Induced charge on the outer surface of the inner shell = -Q

NOW,

The potential difference between the two shells 

V=\frac{Q}{4\pi \epsilon _0r_2}-\frac{Q}{4\pi \epsilon _0r_1}

Now Capacitance is given by

C=\frac{Charge(Q)}{Potential\:difference(V)}

C=\frac{Q}{\frac{Q(r_1-r_2)}{4\pi \epsilon _0r_1r_2}}=\frac{4\pi \epsilon _0r_1r_2}{r_1-r_2}

Hence proved.

 

Posted by

Pankaj Sanodiya

View full answer

Crack CUET with india's "Best Teachers"

  • HD Video Lectures
  • Unlimited Mock Tests
  • Faculty Support
cuet_ads