Question

which of the following has the longest wavelength?
red light
gamma
uv
microwave

Explanation:

The electromagnetic spectrum orders waves by wavelength (longest to shortest: radio, microwave, infrared, visible (red to violet), UV, X - ray, gamma). Among the options: red light is visible, gamma and UV are shorter - wavelength than visible, and microwaves have longer wavelengths than visible light (including red light). So microwave has the longest wavelength here.

Answer:

Microwave