Properties of Electromagnetic Waves in Free Space

Steps:

• Electromagnetic waves consist of oscillating electric and magnetic fields perpendicular to the direction of propagation.
• These waves are transverse, not longitudinal, as the oscillations are at right angles to travel.
• In free space (vacuum), all electromagnetic waves travel at the constant speed of light, c ≈ 3 × 10^8 m/s.
• This speed is independent of wavelength or frequency, per Maxwell's equations.

Why D is correct:

• Electromagnetic waves are transverse, and their speed in free space is c = 1/√(μ₀ε₀), constant for all wavelengths.

Why the others are wrong:

• A: Electromagnetic waves are transverse, not longitudinal; speed is constant, not faster for shorter wavelengths.
• B: Electromagnetic waves are transverse, not longitudinal.
• C: Electromagnetic waves are transverse, but speed is the same, not faster, for all wavelengths.

Final answer: D