A ray of light of wavelength `u_(0)` and frequency `v_(0)` enters a glass slab of refractice index `mu` from air. Then

Options

A. its wavelength increases, frequency decreases
B. its wavelength decreases, frequency remains same
C. its wavelength increases, frequency remains same
D. `Delta lambda = lambda_(0) ((1)/(mu) - 1)` and `Delta upsilon = 0`

Answer

b.,d

Explanation

Whenever a ray goes from one medium to another, its frequency remains same. Its wavelength changes in accordance
with `mu lambda =` constant. i.e.,
`mu_(0) lambda)(0) = mu lambda` `(because mu_(0) = mu_("air") = 1)`
`lambda = (lambda_(0))/(mu) (lt lambda)`
So, `lambda` decreases when it goes from rarer to denser medium and vice versa.
`Delta lambda = lambda - lambda_(0)`
`Delta lambda = lambda_(0) ((1)/(mu) - 1)`