Electromagnetic waves in the spectrum

Steps:

• Electromagnetic waves are transverse waves produced by oscillating electric and magnetic fields, traveling through vacuum.
• The spectrum includes radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.
• Evaluate options: Identify which pairs consist entirely of electromagnetic waves.
• Select the option where both waves are electromagnetic.

Why D is correct:

• X-rays and microwaves are both electromagnetic waves, as defined by Maxwell's equations, spanning high- and low-frequency regions of the spectrum.

Why the others are wrong:

• A: Sound waves are mechanical longitudinal waves requiring a medium, not electromagnetic.
• B: Ultrasound is a mechanical sound wave, not electromagnetic, though ultraviolet is.
• C: Water waves are mechanical surface waves, not electromagnetic, though infrared is.

Final answer: D