Question

The capacitance of two concentric spheres of radii R1 and R2 is ( )​

Answer 1

Answer:

-$-\int\limits^R_r {kQ/r^2} \, dr$

Explanation:

C = Q/V

E =kQ²/R

dV = E dr = -kQ²/R dR

Integrating from R1 to R2 ( i have taken R1 as r and R2 as R)

we get

-$-\int\limits^R_r {kQ/r^2} \, dr$

Now to find capacitance, we get

C = Q/V

Substituting V in the equation

C = (4Πε)/(1/r - 1/R)