The speeds of red light and yellow light are exactly equal

Step-by-step solution

In vacuum, all electromagnetic waves travel with the same speed c = 3 10^8 m/s , regardless of their wavelength. Thus, the speeds of red and yellow light are exactly equal in vacuum. In a material medium like air, the speed of light is given by v = c , where is the refractive index of the medium. According to Cauchy's relation, the refractive index depends on the wavelength as = A + B ^2 . Since the wavelength of red light is greater than that of yellow light ( _ red > _ yellow ), the refractive index of air for re