A point charge +Q is located on the x axis at x = a, and a second point charge –Q is located on the x axis at x = –a. A Gaussian surface with radius r = 2a is centered at the origin. The flux through this Gaussian surface is

Net flux through the surface is zero.

Explanation:

Recall that the net electric flux through a closed surface depends on the net charge enclosed inside that surface.

In our case, there are two point charges of exactly opposite charge (net charge - zero), which are located inside the Gaussian surface of radius "2 a" centered at the origin - both charges are located at a distance "a" from the origin of coordinates, therefore inside the Gaussian surface.

Then the net flux through the surface is also ZERO.

for this one it would be d bump/forearm pass

a

explanation:

no diagram was provided, but i'm guessing it's the one i've attached to my answer.

here, a mechanical force turns the rod.   this generates an electric current in the coil, which powers the bulb.