Login/Sign Up
A short pulse of white light is incident from air to a glass slab at normal incidence. After travelling through the slab, the first colour to emerge isa) blueb) greenc) violetd) red
A short pulse of white light is incident from air to a glass slab at normal incidence. After travelling through the slab, the first colour to emerge is
a) blue
b) green
c) violet
d) red
CBSE | Class 12 | NCERT Exemplar | Physics | Ray Optics and Optical Instruments
A short pulse of white light is incident from air to a glass slab at normal incidence. After travelling through the slab, the first colour to emerge is
a) blue
b) green
c) violet
d) red

Answer:

d) Red

The relation v = fλ describes the velocity of a wave. The frequency of light does not change when it travels from one medium to another. As a result, the bigger the wavelength, the faster the speed. The red light has the longest wavelength and thus the fastest speed. As a result, the red colour emerges first after passing through the slab.

 

i

More Material