Electromagnetic Spectrum Components

Steps:

• Electromagnetic waves are transverse waves that travel through vacuum and include radio, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.
• Mechanical waves, like sound or water waves, require a medium and are not part of the electromagnetic spectrum.
• Review options: A pairs light (electromagnetic) with sound (mechanical); B pairs water waves (mechanical) with infrared (electromagnetic); C pairs ultrasound (mechanical sound) with ultraviolet (electromagnetic); D pairs X-rays and microwaves (both electromagnetic).
• Select the option where both are electromagnetic waves.

Why D is correct:

• X-rays and microwaves are defined as electromagnetic waves in the spectrum, produced by accelerating charges and characterized by their wavelengths and frequencies per Maxwell's equations.

Why the others are wrong:

• A: Sound is a longitudinal mechanical wave requiring a medium, unlike electromagnetic waves.
• B: Water waves are mechanical surface waves driven by gravity or wind, not electromagnetic.
• C: Ultrasound is high-frequency mechanical sound waves propagating through matter.

Final answer: D