Question

In the general formula for the potential due to a dipole, setting θ = 0° and θ = 90° respectively recovers which two special cases?

Options

• The equatorial case and the axial case

• The axial case and the equatorial case (V = 0)

• Both settings give V = 0

• Both settings give the axial case

Answer 1

Setting θ = 0° gives cos θ = 1, so V = p/(4πε₀r²), the axial-point result. Setting θ = 90° gives cos θ = 0, so V = 0, the equatorial-point result. The general formula thus contains both special cases.