To find the wavelength of the refracted light in a medium with a refractive index of 2, we can use the relationship between frequency, wavelength, and the speed of light. The frequency ( ) of the light remains the same when it enters the medium.

The formula relating frequency, wavelength, and velocity is:

Where:
is the speed of light in the medium, is the frequency of the light,
is the wavelength of the light. The wavelength of light in the medium ( can be found using the refractive index and the wavelength in a vacuum ( ) as follows:

Given:

Frequency of the light,
Speed of light in a vacuum,

Refractive index of the medium,
First, calculate :

Now calculate :

Converting to nanometers:

Therefore, the wavelength of the refracted light in the medium is .