A solid sphere of +20C with radius a=1m. A conducting spherical shell of -30C with radius b=2m and c=3m is concentric with the solid sphere.(adsbygoogle = window.adsbygoogle || []).push({});

1. Find the inner and outer surface charge of the conducting spherical shell.

My attempt: I just eyeballed it and said -20C is on the inner shell b/c the +20C is attracting it and the rest -10C is on the outer shell.

2. Graph V vs r(the radius from the center).

My attempt: I calculated V at each of the regions.

region 1: r<1 the V due to a solid sphere is (kQ/2R)(3-r^2/R^2)=30k-10r^2

region 2: 1<r<2 V=kQ/r=20k/r

region 3: 2<r<3 r=0

region 4: r>3 V=-10k/r

I attached my graph which i drew on paint.

you can't see 0 between 2&3 but it's there.

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# Homework Help: Equipotential, can someone check my work?

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