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Tanishq Nandan
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Homework Statement
A solid conducting sphere having a charge Q is surrounded by an uncharged concentric conducting hollow spherical shell.Let the potential difference between the surface of the solid sphere and that of the outer surface of the hollow shell be V.If the shell is now given a charge of -3Q,the new potential difference between the same two surfaces is
A)V B)2V C)4V D)-2V
Homework Equations
▪Potential of a spherical shell of radius R having charge Q=kQ/R
▪Charge on conductors resides only on the surface.
The Attempt at a Solution
First case:
Charge on inner sphere:+Q
Charge on inner surface of outer conducting shell: -Q
Charge on outer surface of outer conducting shell: +Q
According to question,V diff between sphere and outer surface of shell is asked.
Assuming radius of inner sphere to be r1 and outer shell to be r2
So,difference is equal to:kQ(1/r1 - 1/r2)
2nd case:
Charge on inner sphere:+Q
Charge on inner surface of outer conducting shell: -Q
Charge on outer surface of outer conducting shell: -2Q
Same method,p.d comes out to be:kQ(1/r1 + 2/r2)
Now,how do I relate this to the original V??
Answer is V,so I'm most probably writing down the potential difference in the 2nd case wrong...
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