Question

An isolated charged conducting sphere of radius 16.0 cm creates an electric field of 4.90 × 104 N/C at a distance 20.0 cm from its center. (a) What is its surface charge density? uC/m2 (b) What is its capacitance? pF

Answer 1

Radius of an isolated charged conducting T = 16.0 cm Electric field = 4.90 times 10^4 N/c Distance of Electric field = 20.0 cm Electric field: An electric field is a vector field that shows the direction that a positively charged particle will move when placed in the field. Electric fields are produced around \r\n objects that have electrical charge, or by a magnetic field that changes with time. E = kq/r^2 4.9 times 10^4 = 9 times 10^9 times q/(0.20)^2 0.225 times 10^12 times q = 4.9 times 10^4 rightarrow values are substituted q = 4.9 times 10^4/0.225 times 10^12 q = 2.177 times 10^-7 c surface charge density: sigma = Q/4 pi R^2 = 2.177 times 10^-7/4 pi times (0.16)^2 sigma = 0.6767 times 10^-6 c/m^2 sigma = 0.6767 mu c/m^2 This charge density is defined as a measure of electric charge per unit volume of the space in one, two or three dimensions. Capacitance of a charge density: c = mu pi epsilon middot R