Question

The surface density on the copper sphere is σ. The electric field strength on the surface of the sphere is

• A. σ
• B. $\frac{\sigma}{2}$
• C. $\frac{\sigma}{\varepsilon_{0}}$
• D. $\frac{\sigma}{2\varepsilon_{0}}$

Answer 1

Answer: (C)

$\frac{\sigma}{\varepsilon_{0}}$

Answer 2

Charge on the sphere = $4\pi R^{2}\sigma$

Where σ = surface density = charge per unit Surface area

$E = \frac{1}{4\pi\varepsilon_{0}} \times \frac{ch\arg e}{R^{2}}$ = $\frac{1}{4\pi\varepsilon_{0}} \times \frac{4\pi R^{2}\sigma}{R^{2}} = \left( \frac{\sigma}{\varepsilon_{0}} \right)$