A hollow cylinder has a charge `q C` within it. If `phi` is the electric flux in unit of voltmeter associated with the curved surface `B` the flux linked with the plance surface `A` in unit of voltmeter will be

Options

A. `1/2(q/(epsilon_0)-phi)`
B. `q/(2epsilon_0)`
C. `phi/3`
D. `q/(epsilon_0)-phi`

Answer

A

Explanation

`phi_("Total")= phi_A+phi_B+phi_C=q/(epsilon_0)`
Since, `phi_B = phi and phi_A = phi_C = phi ` [assumed]
`:. 2phi.=(q)/(epsilon_0)-phiimplies1/2(q/(epsilon_0)-phi)=phi`