An isolated conductor of arbitrary shape has a net charge of $+12\times 10^{- 6}$ C. Inside the conductor is a cavity within which is a point charge $q = +3.7 \times 10^{-6}$ C. In Coulombs, what is the charge (a) on the cavity wall and (b) on the outer surface of the conductor?

Question

austinl · Answer

Taylor, as much as I love your sense of humor... I actually do need help with this problem.
It is stumping me.

taylor<3srin · Answer

Try Thomaster?

austinl · Answer

If TuringTest were on he could help me, he spend forever yesterday helping me.

austinl · Answer

@thomaster 
Any thoughts my friend?

happinessbreaksbones · Answer

@e.mccormick

austinl · Answer

Would we just use the Gauss' law to find the charge on the wall? Or does that only work for electrical flux?

random231 · Answer

oh sorry dear austin i didnt read the question properly! :(((
sorry brother for the confusion ill delete the post.

random231 · Answer

ok it isnt specified that whether the net charge includes the charge in the cavity.

austinl · Answer

I am so confused by this question...

random231 · Answer

see if this helps @austinL : http://www.physics.rutgers.edu/ugrad/227/L4%20Gauss%20Law%20Conductors%20in%20Electrostatics.pdf

austinl · Answer

Okay, if I read this right... The charge on the inside wall is equal to the charge contained in the cavity?

anonymous · Answer

inside the cavity wall it will be -3.7 X 10^-6 and on the outer wall +15.7 X 10^-6

austinl · Answer

Just add them for the outer wall?

austinl · Answer

Those were correct, awesome.

anonymous · Answer

yep for balancing -3.7 it will be added

random231 · Answer

yay

random231 · Answer

actually the charge inside the cavity is distributed in such a way that the electric field at any pt inside the cavity is 0.

random231 · Answer

also this will help u @austinL : http://www.davidpace.com/physics/em-topics/charge-density-concentric-spheres.htm

austinl · Answer

Thanks guys!