Question

For a dielectric, the condition to be satisfied is

(a) σ/ωε > 1

(b) σ/ωε < 1

(c) σ = ωε

(d) ωε = 1

I had been asked this question in an international level competition.

This intriguing question originated from Lossy and Lossless Dielectrics topic in portion EM Wave Propagation of Electromagnetic Theory

Answer 1

Correct choice is (b) σ/ωε < 1

To elaborate: In a dielectric, the conductivity will be very less. Thus the loss tangent will be less than unity. This implies σ/ωε < 1 is true.