The wavelengths for the light of red and blue colours are roughly 7 . 8 × 10 - 7 m and 4 . 8 × 10 - 7 m respectively. Which colour has the greater speed in glass?

In glass, red light has a greater speed.In the vacuum, the light of different colours travels with the same speed. But in mediums like water, light travel with different speeds. In a glass, the red light travels the fastest and the violet light travels the slowest of all the seven colours. When wavelength increases, speed also increases. Hence, light with maximum wavelength travels with maximum speed.

The wavelengths for the light of red and blue colours are roughly 7 . 8 × 10 - 7 m and 4 . 8 × 10 - 7 m respectively. Which colour has the greater speed in glass?

In glass, red light has a greater speed.In the vacuum, the light of different colours travels with the same speed. But in mediums like water, light travel with different speeds. In a glass, the red light travels the fastest and the violet light travels the slowest of all the seven colours. When wavelength increases, speed also increases. Hence, light with maximum wavelength travels with maximum speed.