Engineering Electromagnetics Fundamentals Flashcards

The electric flux density D and electric field E in a linear isotropic dielectric are related by:

Answer: D = ε₀εᵣE

In a linear isotropic medium, D = ε₀εᵣE = εE, where εᵣ is the relative permittivity.

The magnetic vector potential A is defined such that:

Answer: B = ∇×A

The magnetic flux density is defined as B = ∇×A, automatically satisfying ∇·B = 0.

Standing waves on a transmission line occur when:

Answer: The load is mismatched (Γ ≠ 0)

A mismatched load causes a reflected wave; the incident and reflected waves superpose to form standing waves.

The electric field intensity E is related to the scalar potential V and vector potential A by:

Answer: E = -∇V - ∂A/∂t

In the general time-varying case, E = -∇V - ∂A/∂t, reducing to E = -∇V in electrostatics.

The condition for total internal reflection at a dielectric interface is that the angle of incidence θᵢ satisfies:

Answer: θᵢ > θ_c where sin θ_c = n₂/n₁ (n₁ > n₂)

Total internal reflection occurs when θᵢ exceeds the critical angle θ_c = arcsin(n₂/n₁) for n₁ > n₂.

Which of the following correctly states Faraday's law in integral form?

Answer: ∮E·dl = -d/dt ∬B·dS

Faraday's law states that the EMF around a closed path equals the negative rate of change of magnetic flux through the surface.

The phase velocity of a wave in a medium with relative permittivity εᵣ and relative permeability μᵣ is:

Answer: v_p = c / √(εᵣμᵣ)

Phase velocity is v_p = 1/√(με) = c/√(εᵣμᵣ), always less than or equal to c in passive media.