Wavelength in Microwave Region

Steps:

• Identify the electromagnetic spectrum ranges: radio waves (>1 mm), microwaves (1 mm–1 m), infrared (700 nm–1 mm), visible (400–700 nm), ultraviolet (<400 nm), X-rays (0.01–10 nm), gamma (<0.01 nm).
• Convert 2 cm to 0.02 m, which falls between 1 mm (0.001 m) and 1 m.
• Match to microwave band, as it aligns with wavelengths for microwave radiation detection.
• Select telescope type specialized for that band.

Why A is correct:

• Microwave telescopes detect radiation in the 1 mm–1 m range, per electromagnetic spectrum definitions, ideal for 2 cm wavelengths.

Why the others are wrong:

• B: Optical telescopes target visible light (400–700 nm), far shorter than 2 cm.
• C: Radio telescopes focus on longer wavelengths (>1 m), not specifically 2 cm microwaves.
• D: X-ray telescopes detect very short wavelengths (0.01–10 nm), much smaller than 2 cm.

Final answer: A