When white light is incident on a glass slab, red light emerges first, the reason being (vel )=(freq lambda) - Physics - Ray Optics And Optical Instruments

Question

When white light is incident on a glass slab, red light emerges
first, the reason being (vel )=(freq ?lambda) which implies that ve
is directly prop to lambda But can't we also say that vel is
directly proportional to freq and hence it should be violet
emerging first?

Shivam Pratap Singh · Accepted Answer

Dear student

Frequency of light does not depend on colour, it is same for all
colours as it only depends on the source which has produced rays As
frequency is same for all colours so we can not compare velocity of
colours on the basis of frequency hence we can not say violet
emerges out first on the basis of frequency

With regards

When white light is incident on a glass slab, red light emerges first, the reason being (vel.)=(freq.?lambda) which implies that ve. is directly prop. to lambda. But can't we also say that vel. is directly proportional to freq. and hence it should be violet emerging first?