The red light from the ant passed into the lens

as the light enters the lens, state what happens to

1. its wavelength
2. its frequency

When red light enters the lens its wavelength decreases but its frequency remains the same.

Explanation:

Lens is made of glass which is a denser medium when compared with air. Thus light will undergo refraction and bend toward the normal. On entering  a denser medium from rarer medium the speed of light decreases.

Speed, frequency and wavelength of an electromagnetic wave are related according to the equation.

                                                                v=ϑλ

Where is v is the frequency,  λ is the wavelength and v is the speed of the em wave.

On entering the lens the wavelength of the red light as well as speed decreases but the frequency remains the same.