A disc of radius `a//4` having a uniformly distributed charge `6C` is placed in the x-y plane with its centre at `(-a//2, 0, 0)`. A rod of length a carrying a uniformly distributed charge 8C is placed on the x-axis from `x=a//4` to `x=5a//4`. Two point charges `-7C` and `3C` are placed at `(a//4, -a//4, 0)` and `(-3a//4, 3a//4, 0)`, respectively. Conisder a cubical surface formed by isx surfaces `x=+-a//2`, `y=+-a//2`, `z=+-a//2`. The electric flux through this cubical surface is

Options

A. `(-2C)/(epsilon_(0))`
B. `(2C)/(epsilon_(0))`
C. `(10 C)/(epsilon_(0))`
D. `(12 C)/(epsilon_(0))`

Answer

1

Explanation

Total charge inside cube
`q_("in") = 3 C + 2C - 7C = - 2 C`
`phi = (q_("in"))/(in_(0)) = - (2 C)/(in_(0))`