For a cell, the terminal potential difference is `2.2 V`, when circuit is open and reduces to `1.8 V `. When cell is connected to a resistance `R=5Omega`, the internal resistance of cell `(R)` is

Answer

`Oc = (2pi)/(3(4 - pi))`

Explanation

`x_(cm) = ((rho2r^(2)) (r )/(2) - (rho(pir^(2))/(2)) ((4r)/(3pi)))/((rho2r^(2)) - (rho(pir^(2))/(2)))= (2r)/(3(4 - pi))`