Question

In glass, violet light travels faster than red light. Is the statement true?

Answer 1

No, Violet ray travels slowest among all the light . The wavelength of the violet light is minimum.

Wavelength of a particular colour in medium ${\lambda }^{\prime }=\frac{{\lambda }_{air}}{n}$

Frequency for all colors is same $velocity=frequency\times wavelength$.

Hence ray with minimum wavelength travels slowest.