A cubical region of side a has its centre at the origin. It encloses three point charges , `-q` at `(0, -a//4 , 0),+3q at (0,0,0)` and `-q` at `(0,+a//4 ,0)`.
Choose the correct option (s)

(i) The net electric flux crossing the plane `x = +(q)/(2)` is equal to the net electric flux crossing the plane `x = -(a)/(2)`
(ii) The net electric flux crossing the plane `y = +(a)/(2)` is more than the net electric flux crossing the plane `y = -(a)/(2)`
(iii) The net electric flux crossing the entire region is `(q)/(epsilon_(0))`
(iv) The net electric flux crossing the plane `z = +(a)/(2)` is equal to the net electric flux crossing the plane `x = +(a)/(2)`

Options

A. `(i),(ii)`
B. `(i),(iii)`
C. `(i),(iii),(iv)`
D. `(ii),(iii),(iv)`

Answer

3

Explanation

For `x = + (a)/(2) , x = -(a)/(2) , y = (a)/(2),y = -(a)/(2),z = (a)/(2), z = -(a)/(2)`
Charges are placed symmetrically
Total flux `phi = (3q - q - q)/(in_(0)) = (q)/(in_(0))`