Question

1.2. Two charges of magnitudes -40 and +2Q are located at points (2a, 0) and (5a, 0 respectively. What is the electric flux due to these charges through a sphere of radius 4a with its centre at the origin? is: +20 O 40 X X2 4a​

Answer 1

Flux(ϕ)=

ϵ

0

q

where, q is the total charge inside the surface

Here, q=−2Q and gaussian surface is a sphere of radius 3a and center at origin.

So,Flux(ϕ)=

ϵ

0

−2Q

Here, flux is only due to charge -2Q because no. of field lines enter the sphere due to charge +Q is equal to no. of field lines coming out of the sphere, so net flux is zero due to charge +Q.