Answers

2016-02-15T18:03:15+05:30
Gauss’ theorem states that the electric flux through a closed surface enclosing a charge is equal to times the magnitude of the charge enclosed.The sphere enclose charge = +4Q.Thus,
Sphere of radius a , centre at the origin will contain only charge which is present at (a,0), so net charge enclosed  is 

+4Q .
Ф=4Q/ε

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