Recent content by RobTwox

I have a new thought. I looked up surface current density and found that the units are A / m^2. if this is true then this boils down to current per area. So, could I say (and be correct) that the current I will be uniformly distributed and constant. Then to write a general expression for...

Homework Statement Electric current of I amperes flows along the z-axis from (0, 0,-∞) to (0, 0, -a) and from there it spreads over a conducting sphere r = a in the -aθ direction, comes to the point (0; 0; a) and goes to (0, 0, ∞) again along the z-axis. What is the surface current density at...

I can tell that this tried your patience. I want you to know that I am so grateful that you stuck it out with me. I am even more grateful that you did not jst give me the answer. Thank you so much

It should be the same magnitude as +y but opposite direction I think

SO we have E = 2 ρv / ε0 If this is correct then it implies that distance does not matter once outside of the wall. Is this right

this is D⋅ds so D L H

Qenc = ρv * volume. volume is y * L * H and y =2 so Qenc = ρv 2 H L

ok, so if I express w in terms of y is it E= y ρv / ε0

ρv * Volume = ρv L W H but I guess if the box is half full I could say ρv L W H / 2Is any of this right?

w = 2 so E= 2 ρv / ε0 I don't understand how a partially filled box will change things. Dosent the flux still come through just the same?

alrighty then so if I set eqns equal to each other D= ρv W / ε0 wont the expression be the same for the outside of wall case? I know I have to get rid of the w this is not given how do I do this?

ok then I need to set up ∫D⋅ds isn't this just D * surface area or D L H

lets deal with case 1 first where the box is completely inside. at this point the outside face will be the only one with flux thru. the flux will be parallel to all other faces. Am I right?

ok if 1 face is at y =0 then that face has no flux through. The only face we care about is the one poking out the side (that's where we are asked to find E) but the top and bottom would have flux too. so Qenc =ρv L W H and then I'm not sure what to do with the integral if I do ∫d⋅dv then I get D...

I'm really lost with this. We are just covering gauss law this is my first problem