Difficulty: Easy
Correct Answer: All of these
Explanation:
Introduction / Context:Maxwell’s equations predict coupled electric (E) and magnetic (H) fields forming a transverse wave. Understanding their geometry and polarisation is fundamental in optics, antennas, radar, and remote sensing calibration.
Given Data / Assumptions:
Concept / Approach:In free space, E ⟂ H ⟂ k (propagation direction). For propagation along z, E and H lie in the XY plane. Polarisation specifies how the E-field vector is oriented (and evolves) in time and space (linear, circular, elliptical).
Step-by-Step Reasoning:
1) Composition: EM waves comprise E and H fields.2) Orthogonality: E ⟂ H and both are transverse to k.3) Directional example: k along z ⇒ E in XY; H also in XY and orthogonal to E.4) Polarisation: orientation/trajectory of E defines wave polarisation state.Verification / Alternative check:Antenna polarisations (H/V, RHCP/LHCP) demonstrate practical importance for link budgets and scattering behaviour.
Why Other Options Are Wrong:
Common Pitfalls:Assuming longitudinal components exist in free space plane waves; mixing up polarisation of E vs H (E defines polarisation by convention).
Final Answer:All of these
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