Question

A metallic sphere of radius \( R \) is charged to a potential \( V \). The magnitude of the electric field at a distance \( r \, (r > R) \) from the center of the sphere is:

• A. \( \frac{V}{r^2} \)
• B. \( \frac{VR^2}{r^2} \)
• C. \( \frac{V}{R^2} \)
• D. \( \frac{V}{r} \)

Hint:

For a metallic sphere, the electric field outside the sphere behaves as if the entire charge is concentrated at the center. To calculate the electric field, use the formula \( E = \frac{1}{4\pi\epsilon_0} \cdot \frac{Q}{r^2} \), where \( Q \) is the charge and \( r \) is the distance from the center of the sphere.