Q.

A monochromatic light wave with wavelength λ1 and frequency ν1 in air enters another medium. If the angle of incidence and angle of refraction at the interface are 45° and 30° respectively, then the wavelength λ2 and frequency ν2 of the refracted wave are                         [2023]

1 λ2=12λ1, ν2=ν1  
2 λ2=λ1, ν2=12ν1  
3 λ2=2λ1, ν2=ν1  
4 λ2=λ1, ν2=2ν1  

Ans.

(1)

Snell's law μ1sin45°=μ2sin30°

μ1μ2=12

 μ1μ2=λ2λ1=12

 λ2=λ12

Frequency doesn't change on change in medium.