Electromagnetic Waves — Class 12 Physics NCERT Solutions (Free)
Free step-by-step NCERT solutions for Class 12 Physics chapter "Electromagnetic Waves" — 8 important questions with detailed answers for CBSE board exam preparation.
TL;DR: Free step-by-step NCERT solutions for Class 12 Physics chapter "Electromagnetic Waves" — 8 important questions with detailed answers for CBSE board ex…
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Key Questions Covered:
- What is an electromagnetic wave? Write its characteristics.
- Derive the relationship between c, μ₀, and ε₀ for speed of electromagnetic wa…
- What is meant by polarization of an electromagnetic wave? Describe linear and…
- + 5 more questions in the full chapter
Solutions Summary:
| Question | Status |
|---|---|
| What is an electromagnetic wave? Write its characteristics. | ✓ Solved |
| Derive the relationship between c, μ₀, and ε₀ for speed o… | ✓ Solved |
| What is meant by polarization of an electromagnetic wave?… | ✓ Solved |
Showing 3 of 8 questions
Q1: What is an electromagnetic wave? Write its characteristics.
An electromagnetic wave is a transverse wave consisting of time-varying electric and magnetic fields perpendicular to each other and to the direction of propagation.
Characteristics:
1. Transverse in nature — E and B oscillate perpendicular to direction of propagation
2. E and B are perpendicular t...
Q2: Derive the relationship between c, μ₀, and ε₀ for speed of electromagnetic waves.
From Maxwell's equations:
∇ × E = -dB/dt (Faraday's law)
∇ × B = μ₀ε₀(dE/dt) (Ampere-Maxwell law)
For a plane wave traveling in +x direction:
E = E₀ sin(kx - ωt)
B = B₀ sin(kx - ωt)
From Faraday's law:
-dE/dx = dB/dt
-E₀k cos(kx - ωt) = -B₀ω cos(kx - ωt)
E₀k = B₀ω
E₀/B₀ = ω/k = v
From Ampere-Max...
Q3: What is meant by polarization of an electromagnetic wave? Describe linear and circular polarization.
Polarization: Restriction of oscillation of electric field vector E to a particular direction perpendicular to propagation.
Linear (plane) polarization:
- E oscillates along a fixed direction (one plane)
- E⃗ = E₀ sin(kx - ωt) ĵ (for oscillation in y-direction)
- Can be obtained using polarizers (N...
Showing 3 of 8 questions. Visit the full page for complete solutions.