Which of the following statements is/are true regarding a light wave travelling from air to glass?

1. Its frequency remained unchanged.
2. Its speed changes.

Select the correct answer using the codes given below.
a) 1 only
b) 2 only
c) Both 1 and 2
d) None of the above

Ans–c

Explanation– This is process of refraction being talked about. In refraction speedand wavelength of light changes as shown here. Frequency remains unchanged. This is because the electric and magnetic fields have to remain continuous at the refractive index boundary.