Question

Nobody ever helps me on physics unless I pay for it and they dont even help me that well. ... What's up with the physics tutors? Could somebody help me understand why these answers are correct?

http://s11.postimg.org/r41uwy8bn/Question_1.png

Answer 1

Flux, Φ, is equal to the charge inside, q, divided by the permissibility, ε:

Φ = q / ε

It does not depend on nothing but the charge inside, since ε is constant.

(a) If the charge is tripled the flux will be tripled.
(b) If the volume of the sphere is doubled the flux will remain the same, since it doesn't depend on the distance to the surface.
(c) The flux will remain the same because it is not dependent on the form of the surface.
(d) As long as it is inside the flux will remain the same.
(e) The flux will be zero, because flux is proportional to the charge inside. All the electric field lines that enter the surface will also exit, therefore the flux is zero.