Electromagnetic Waves and Communication System

Answer

EM waves are periodic changes in electric and magnetic fields that propagate through space. They are produced by accelerated electric charges. According to Maxwell's theory, when charges oscillate, th

Answer

1. Gauss' law for electrostatics: ∮ E⃗ · dS⃗ = Qin/ε₀ (relates electric charge to electric field) 2. Gauss' law for magnetism: ∮ B⃗ · dS⃗ = 0 (no magnetic monopoles exist) 3. Faraday's law: ∮ E⃗ · dl⃗

Answer

1. E⃗ and B⃗ are perpendicular to each other and to direction of propagation (transverse waves) 2. E⃗ × B⃗ gives direction of propagation 3. E⃗ and B⃗ vary sinusoidally and are in phase 4. Travel at s

Answer

The speed of EM waves in vacuum is: c = 1/√(μ₀ε₀) Where: μ₀ = 4π×10⁻⁷ Tm/A (permeability of free space) ε₀ = 8.85×10⁻¹² C²/Nm² (permittivity of free space) c = 1/√(4π×10⁻⁷ × 8.85×10⁻¹²) = 3.00×10⁸ m/s

Answer

Given: E₀ = 100 V/m For EM waves: |E₀|/|B₀| = c Therefore: B₀ = E₀/c = 100/(3×10⁸) = 3.33×10⁻⁷ T The magnetic field amplitude is 3.33×10⁻⁷ T.

Answer

The EM spectrum is the orderly distribution of EM waves according to wavelength/frequency. In order of increasing frequency: 1. Radio waves (lowest frequency) 2. Microwaves 3. Infrared radiation 4. Vi

Answer

Radio waves: - Wavelength: 6×10⁻⁴ to 1×10⁵ m (very long) - Source: Acceleration of electrons in circuits - Uses: Broadcasting, communication Gamma rays: - Wavelength: 6×10⁻¹³ to 1×10⁻¹⁰ m (very short

Answer

Properties: - Wavelength: 3×10⁻⁴ to 6×10⁻² m - Heat certain substances - Can be detected by crystal detectors Uses: - TV signal transmission - Long distance telephone communication - Microwave ovens