question_answer

A point charge q is placed at a distance a/2 directly above the centre of a square of side a. The electric flux through the square is                                            [MP PMT 1997; AMU 1999]

A)            \[\frac{q}{{{\varepsilon }_{0}}}\]                                    

B)            \[\frac{q}{\pi {{\varepsilon }_{0}}}\]

C)                    \[\frac{q}{4{{\varepsilon }_{0}}}\]                          

D)            \[\frac{q}{6{{\varepsilon }_{0}}}\]

Correct Answer: D

Solution :

           An imaginary cube can be made by considering charge q at the centre and given square is one of it's face. So flux from given square (i.e. one face) \[\varphi =\frac{q}{6{{\varepsilon }_{0}}}\]