Which of the following electromagnetic waves has the longest wavelength?

Solution

1. The electromagnetic spectrum consists of waves ranging from high-frequency, short-wavelength radiation to low-frequency, long-wavelength radiation.
2. Radio waves are located at the end of the spectrum characterized by the lowest frequencies and the longest wavelengths.
3. In contrast, gamma rays, X-rays, and ultraviolet rays occupy the high-frequency, short-wavelength end of the spectrum.
4. Comparing the options, radio waves possess the greatest wavelength among the listed types of electromagnetic radiation.
5. Hence the answer is (B).