Question

A photon of light enters a block of glass after travelling through a vacuum. The energy of the photon on entering the glass block

• A. Increases because its associated wavelength decreases
• B. Decreases because the speed of the radiation decreases
• C. Stays the same because the speed of the radiation and the associated wavelength do not change
• D. Stays the same because the frequency of the radiation does not change

Answer 1

Answer: (D)

Frequency of light does not change with medium, it is the property of the wave from wave source and the energy of a photon is given by $E=h\nu$ . Here, $\nu$ is the frequency.