Question

The expression for intrinsic impedance is given by

(a) √(με)

(b) (με)

(c) √(μ/ε)

(d) (μ/ε)

This question was addressed to me by my college professor while I was bunking the class.

My question comes from Plane Waves in Dielectrics in section EM Wave Propagation of Electromagnetic Theory

Answer 1

The correct option is (c) √(μ/ε)

The explanation is: The intrinsic impedance is given by the ratio of square root of the permittivity to the permeability. Thus η = √(μ/ε) is the intrinsic impedance. In free space or air medium, the intrinsic impedance will be 120π or 377 ohms.