Classifying EM waves by wavelength ranges

Steps:

• Recall EM spectrum ranges: visible (4×10^{-7}–7×10^{-7} m), ultraviolet (<4×10^{-7} m), infrared (7×10^{-7}–10^{-3} m), microwave (10^{-3}–1 m).
• Compare first wavelength (5.0×10^{-7} m) to ranges: falls within visible light.
• Compare second wavelength (5.0×10^{-2} m or 5 cm) to ranges: falls within microwave.
• Match pair to choices: visible and microwave corresponds to option B.

Why B is correct:

• Visible light spans ~400–700 nm (4–7×10^{-7} m), matching 5.0×10^{-7} m; microwaves span ~1 mm–1 m (10^{-3}–1 m), matching 5.0×10^{-2} m per standard EM spectrum definitions.

Why the others are wrong:

• A: Ultraviolet is shorter than visible (<4×10^{-7} m); second wavelength too long for infrared.
• C: Second wavelength too short for microwave (starts at ~1 mm).
• D: Second wavelength too long for infrared (ends at ~1 mm).

Final answer: B