Case: Read the passage and answer the question.
Einstein’s photoelectric equation is
\( K_{\max}=h\nu-\Phi \)
where \( \nu \) is the frequency of the incident radiation and \( K_{\max} \) is the maximum kinetic energy of a photoelectron. The work function \( \Phi \) is given as \( \Phi=h\nu_0 \). In terms of the stopping potential \( V_0 \), \( K_{\max}=eV_0 \).
What can you say about the following statement?
Statement: All photons have the same energy, whatever the frequency of the light.
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → False
Statement: All photons have the same energy, whatever the frequency of the light. — False. In the photon picture, each photon carries energy \( E=h\nu \). So the photon energy depends on the frequency. A photon of violet light carries more energy than a photon of red light. Only photons of light of one particular frequency have the same energy, whatever the intensity. A brighter beam has more photons, but each photon has the same energy as before.
NCERT (2026-27):
Particle Nature of Light: the Photon – “… (ii) Each photon has energy E (=hν) and momentum p (= h ν/c), and speed c, the speed of light. (iii) All photons of light of a particular frequency ν, or wavelength λ, have the same energy E (=hν = hc/λ) and momentum p (= hν/c= h/λ), whatever the intensity of radiation may be.”