Two waves A and B have wavelength 0.01 Å and 9000 Å respectively. (a) Name the two waves. (b) Compare the speeds of these waves when they travel in vacuum.

(a) Wave A is Gamma rays (as the wavelength range of gamma rays is shorter than 0.1 Å). Wave B is Infrared radiations (as the wavelength range of infrared radiations is 8000 Å to 10⁷ Å).

(b) All electromagnetic waves travel with the speed of light (i.e., 3 x 10 ⁸ ) in vacuum. Thus, ratio of speeds of these waves in vacuum is 1 : 1.