The mechanical force per unit charge at a given point is defined as the electric field intensity. The electric field intensity (E) is a vector quantity and is given by the formula:
E = F/Q
where F is the force experienced by a charge Q. The unit of electric field intensity is Newton per Coulomb (N/C).
Let's evaluate the options:
- Electric field intensity: This is the correct definition as it represents the force per unit charge.
- Potential energy: This refers to the energy possessed by an object due to its position or condition, not force per unit charge.
- Permeability: This relates to the ability of a material to support the formation of a magnetic field within itself, not relevant to force per unit charge.
- Permittivity: This is a measure of how an electric field affects, and is affected by, a dielectric medium, not directly force per unit charge.
Thus, the correct answer is Electric field intensity.