Question

a hollow conducting sphere of radius .12 meters has a uniform charge distributed on its surface. the electric field at a distance of .20 meters has a value of 10 n/c. how much charge is distributed on the sphere

Answer 1

$$E=k\frac{q}{r^2}\\10=9\cdot10^{9}\frac{q}{0.2^2}\\q=4.4\cdot10^{-11}C$$