What is the length range given for microwaves?

• A. 3 μm - 3 mm
• B. 1 μm - 1 mm
• C. 3 nm - 3 μm
• D. 10 μm - 1 cm

Answer: (A)

Wavelength determines how we categorize electromagnetic waves, with longer wavelengths sitting at the lower-frequency end of the spectrum and shorter wavelengths at the higher-frequency end. Microwaves sit beyond infrared in wavelength, generally described as occupying the region from about a millimeter up to a few centimeters (though exact cutoffs vary by source). The range given in this context spans from a few micrometers up to a few millimeters, which sits at the boundary where infrared ends and microwaves begin. This makes it the best match among the options for representing a microwave-range in many teaching contexts. The other options either lie mostly in infrared/visible/ultraviolet regions or stop short of the typical microwave extent, so they don’t align as well with how microwaves are defined in standard discussions.