Which of the following radiations has a wavelength longer than that of visible light?
Infrared waves
The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation, which subsumes visible light, as well as invisible radiations such as radio waves, microwave, infrared waves, ultraviolet, X rays, and gamma waves. Visible light have a wavelength range of 400nm- 700 nm.
From the above figure, it is very clear that infrared waves, microwaves and radio waves have wavelength greater than visible light and ultraviolet waves , x-rays and gamma rays have shorter wavelength as compared to visible light.