Answer:
10R/11 and 5R/2
Explanation:
The radius of the conducting shell = R,
Electrostatic potential inside the shell (r<R) = kq/R
Electrostatic potential outside the shell (r>R) = kq/r
If x is the point of zero potential
Electrostatic potential for inner shell, [tex]V_{1} = \frac{kq}{X - R}[/tex]
Electrostatic potential for outer shell, [tex]V_{2} = \frac{-2kq}{X - 2R}[/tex]
Electrostatic potential for the thin walled shell, [tex]V_{3} = \frac{2kq}{X - 5R}[/tex]
[tex]V_{1} + V_{2} + V_{3} = 0[/tex]
[tex]\frac{kq}{X-R} - \frac{2kq}{X-2R} + \frac{2kq}{X-5R} = 0[/tex]
[tex]\frac{1}{X-R} - \frac{2}{X-2R} + \frac{2}{X-5R} = 0\\(X-R) - 2(X-R)(X-5R)+2(X-R)(X-2R) = 0[/tex]
The values of X=r that satisfy the above equation are 10R/11 and 5R/2