Question

Which justification is used for the formula \[E=\frac{\sigma}{\varepsilon_0}\]?

Options

• Charge leakage + permittivity of free space.

• Friction + polarisation.

• Gauss's law + zero field inside conductor.

• Potential difference + spark discharge.

Answer 1

The result follows by applying Gauss's law to a small pillbox at the conductor's surface. The field inside the conductor is zero, leaving flux through the outer face.