question_answer

A solid sphere made of insulating material has a radius R and has a total charge Q distributed uniformly in its volume. What is the magnitude of the electric field intensity, E, at a distance r (0 < r < R) inside the sphere?

A)  \[\frac{1}{4\pi {{\varepsilon }_{0}}}\frac{Qr}{{{R}^{3}}}\]                 

B)  \[\frac{3}{4\pi {{\varepsilon }_{0}}}\frac{Qr}{{{R}^{3}}}\]

C)  \[\frac{1}{4\pi {{\varepsilon }_{0}}}\frac{Q}{{{r}^{2}}}\]                   

D)  \[\frac{1}{4\pi {{\varepsilon }_{0}}}\frac{QR}{{{r}^{3}}}\]