Electromagnetic Waves MCQ [Free PDF] – 5 Objective Questions with Answers

Its characteristic impedance is set by those per-unit-length parameters and frequency, not by line length. A mismatch between load and characteristic impedance causes reflected waves and standing-wave patterns. Key relation: Z₀=√((R+jωL)/(G+jωC)); Γ=(Z_L−Z₀)/(Z_L+Z₀).

Exam focus: Match ZL to Z0 to eliminate reflection. Common trap: Characteristic impedance is not the same as total line impedance.

Using the given constant electric-field magnitude 2 and current density J = x² over x=0 to 1, power is the integral of E·J: ∫₀¹2x²dx = 2/3.

A plane electromagnetic wave can propagate through vacuum without a material medium. In a homogeneous lossless medium, wave speed and intrinsic impedance are set by permittivity and permeability; in free space they reduce to c and about 377 ohms. Key relation: v=1/√(με); η=√(μ/ε); in free space c≈3×10^8 m/s and η0≈377 Ω.

Exam focus: Remember the orthogonal E-H-propagation triad. Common trap: In the elementary nondispersive model, wave speed is not set by frequency.

A plane electromagnetic wave can propagate through vacuum without a material medium. In a homogeneous lossless medium, wave speed and intrinsic impedance are set by permittivity and permeability; in free space they reduce to c and about 377 ohms. Key relation: v=1/√(με); η=√(μ/ε); in free space c≈3×10^8 m/s and η0≈377 Ω.

Exam focus: Remember the orthogonal E-H-propagation triad. Common trap: In the elementary nondispersive model, wave speed is not set by frequency.

The Poynting vector gives electromagnetic power-flow density and points in the direction of energy transport for a propagating wave. It is the cross product of electric and magnetic fields. Key relation: S=E×H [W/m²].

Exam focus: Cross E with H to get energy-flow direction. Common trap: V/m is electric-field unit, not Poynting-vector unit.