Aray of light in air is incident at an angle of 25.0° on a glass slide with index of refraction 1.51. (a) at what angle is the ray refracted? ° from the normal (b) if the wavelength of the light in vacuum is 580 nm, find its wavelength in the glass. nm

16.25° , 348.11 nm

Explanation:

Using Snell's law as:

Where,  

 is the angle of incidence  ( 25.0° )

is the angle of refraction  ( ? )

is the refractive index of the refraction medium  (glass, n=1.51)

is the refractive index of the incidence medium (air, n=1)

Hence,  

Angle of refraction = = 16.25°

Refractive index is equal to velocity of the light 'c' in empty space divided by the velocity 'v' in the substance.

Or ,

n = c/v.

The frequency of the light does not change but the wavelength of the light changes with change in the speed.

c = frequency × Wavelength

Frequency is constant,  

The formula can be written as:

n = λ / λn.

Where,  

λn is the wavelength in the medium  

λ is the wavelength in vacuum (580 nm)

So,

1.51 = 580 /  λn

λn = 348.11 nm