A uniformly charged conducting sphere of $2.4 ext{ m}$ diameter has a surface charge density of $80

Question

A uniformly charged conducting sphere of $2.4	ext{ m}$ diameter has a surface charge density of $80.0\mu C/m^2$. Find the charge on the sphere.

Professor PC Thomas Classes · Answer

Radius $R = 1.2	ext{ m}$. Surface area $A = 4\pi R^2 = 4 	imes 3.1416 	imes 1.44 = 18.095	ext{ m}^2$. Charge $Q = \sigma A = 80.0 	imes 10^{-6} 	imes 18.095 = 1.447 	imes 10^{-3}	ext{ C} \approx 1.45 	imes 10^{-3}	ext{ C}$.