Question

If the wavelength of electromagnetic radiation is doubled, what will happen to the energy of photons?

(a) Remains the same

(b) Doubled

(c) Halved

(d) Infinite

I have been asked this question by my college director while I was bunking the class.

I'm obligated to ask this question of Photoelectric Effect in section Dual Nature of Radiation and Matter of Physics – Class 12

Answer 1

Right choice is (c) Halved

The best I can explain: Energy of a photon is given as:

E = hv = \(\frac {hc}{\lambda}\)

The energy of the photon reduces to one-half when the wavelength of radiation is doubled.