Electrostatics Question 681
Question: A solid conducting sphere of radius a has a net positive charge 2Q. A concluding spherical shell of inner radius b and outer radius c is concentric with the solid sphere and has a net charge-Q. The surface charge density on the inner and outer surfaces charge density on the inner and outer surfaces of the spherical shell will be
Options:
A) $ -\frac{2Q}{4\pi b^{2}},\frac{Q}{4\pi c^{2}} $
B) $ -\frac{Q}{4\pi b^{2}},\frac{Q}{4\pi c^{2}} $
C) $ 0,\frac{Q}{4\pi c^{2}} $
D) None of the above
Show Answer
Answer:
Correct Answer: A
Solution:
[a] Surface charge density $ ( \sigma )=\frac{\text{Charge}}{\text{Surface area}} $ So $ \sigma {= _{inner}}=\frac{-2Q}{4\pi b^{2}} $ And $ \sigma {= _{outer}}=\frac{Q}{4\pi b^{2}} $
