Question

A metal sphere of radius $10cm$ has a charge of $12.56\times {10}^{-6}$ coulomb. The surface charge density on the sphere is :

• A. $1C/m^2$
• B. ${10}^{-6}C/m^2$
• C. ${10}^{-4}C/m^2$
• D. ${10}^{-5}C/m^2$

Answer 1

Answer: (C)

${10}^{-4}C/m^2$

charge on metal sphere always stays on surface
surface charge density $=\frac{Q}{4\pi R^2}$

$\sigma =\frac{12.56\times {10}^{-6}}{4\times 3.14\times (10\times {10}^{-2}{)}^2}$

$\sigma ={10}^{-4}C/m^2$