CBSE Class 12 Physics – Electromagnetic Waves

Chapter Overview

This chapter explains how oscillating electric and magnetic fields propagate through space as waves—without needing a medium—described by Maxwell’s equations. Students study displacement current, wave equations derived from Maxwell’s laws, properties of these transverse waves, the electromagnetic spectrum, speed of light relation, energy and momentum transport, and explore applications like communication and medical imaging technologies.

Important Keywords

• Electromagnetic Wave: Self‑propagating transverse waves of E and B fields. :contentReference[oaicite:1]{index=1}
• Displacement Current: ε₀ dΦ_E/dt, adds to conduction current in Ampère’s law. :contentReference[oaicite:2]{index=2}
• Maxwell’s Equations: Unified laws showing E ↔ changing B and B ↔ changing E generate waves. :contentReference[oaicite:3]{index=3}
• Transverse Wave: E and B oscillate perpendicular to propagation. :contentReference[oaicite:4]{index=4}
• Speed of Light (c): c = 1/√(μ₀ε₀) ≈ 3 × 10⁸ m/s. :contentReference[oaicite:5]{index=5}
• Electromagnetic Spectrum: Ranges from radio to gamma rays with varying uses. :contentReference[oaicite:6]{index=6}
• Energy Density: Both E and B fields share equal energy. :contentReference[oaicite:7]{index=7}
• Photon: Quantum particle of light; EM waves also exhibit particle behavior. :contentReference[oaicite:8]{index=8}