Question

A nonconducting solid sphere of radius 2.20 cm carries a uniformly distributed positive charge of 7.00×10-9 C. Calculate the magnitude of the electric field at a point 1.40 cm away from the center of the sphere. Calculate the magnitude of the electric field at a point 3.20 cm away from the center of the sphere.

Answer 1

radius R = 2.2 cm = 0.022 m
charge q = 7.00×10-9 C
the magnitude of the electric field at a point 1.40 cm away from the center of the sphere E = Kqr / R^ 3
where K = coulomb's constant = 8.99 * 10 ^ 9 Nm^ 2/ C^ 2
r = distance = 1.4 cm = 0.014 m
plug the values we get E = 82.74 * 10 ^ 3 N / C
(b). The magnitude of the electric field at a point 3.20 cm away from the center of the sphere E ' = Kq/ r'^ 2
where r ' = 3.2 cm =0.032 m
plug the values we get E ' = 61.45 * 10^3 N / C