When light is refracted into a medium

Options

A. its wavelength and frequency both increase
B. its wavelength increases but frequency remains unchanged
C. its wavelength decreases and frequency increases
D. its wavelength and frequency both decrease

Answer

B

Explanation

Accoding to Snell.s law `(sini)/(sinr)=(v_(1))/(v_(2))=(mu_(2))/(mu_(1))`
From fig. we see that
`r gt i`
So `v_(2)=n lambda_(2) gt v_(1)=n lambda_(1)`
`rArr lambda_(2) gt lambda_(1)`

(Frequency of wave does not change on refraction)