In a certain region of space the electrostatic field depends only on the coordinates x and y as follows.
`E=0" for "sqrt(x^(2)+y^(2)) lt r_(0)`
`E=a(xhati+yhatj)(x^(2)+y^(2))" for "sqrt(x^(2)+y^(2)) gt r_(0)`
Where a is a positive constant and `hati` and `hatj` are the unit vectors along the X-and Y-axes. find the charge within a sphere of radius `2r_(0)` with the centre at the origin.

Answer

`q=16 pi in_(0)ar_(0)`