Question

In vacuum or free space, what observations are made?

(a) ρ = ρo, J = 0

(b) ρ = 0, J = Jo

(c) ρ = 0, J = 0

(d) ρ = ρo, J = Jo

The question was posed to me in examination.

Origin of the question is Maxwell’s Equations in chapter Electrodynamics of Engineering Physics II

Answer 1

The correct answer is (c) ρ = 0, J = 0

To elaborate: In vacuum or free space, there is no charge or current. Thus, in that case, ρ is equal to zero and the current density, J is also equal to zero.