Find the flux of point charge q through the square surface ABCD as shown `(##JM_21_M2_20210224_PHY_09_Q01##)`

Options

A. (A)`q/6 epsilon_0`
(B)`q/epsilon_0`
(C)`q/4 epsilon_0`
(D)`q/2 epsilon_0`
B. Find the flux of point charge q through the square surface ABCD as shown `(##JM_21_M2_20210224_PHY_09_Q01##)`
C. not varying with `r`
D. varying as `r^2`

Answer

B

Explanation

`El=(dphi)/(dt)=S (dB)/(dt)`
`:. E(2pir)=pir^2(dB)/(dt)`
or `E=r/2 (dB)/(dt)` or `Epropr`