Question

two charges of magnitude -4Q and +Q are located at points (a,0) and (3a,0) respectively. what is the electric field due to these ccharges through a sphere of radius 2a with its centre at the origin

Answer 1

Dear student,
Since the radius of sphere is 2a. so "+Q" charge will be outside the sphere,
so by gauss law,
electric flux will be
$\varnothing =\frac{Q_{enclosed}}{\in }=\frac{-4Q}{\in }$
Regards.