Match List-I with List-II (In the context of a photoelectric effect experiment)
| List-I | List-II |
| (A) For the emission of photo-electrons | (I) governs the maximum kinetic energy of emitted photo-electrons for incident radiation of a particular frequency. |
| (B) Saturation current | (II) depends on the intensity of the incident radiation. |
| (C) The stopping potential | (III) The frequency of the incident radiation ν > threshold frequency ν0 |
| (D) Work function | (IV) measures the maximum kinetic energy of photo-electrons |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → (A) - (III), (B) - (II), (C) - (IV), (D) - (I)
Every item follows from Einstein’s photoelectric equation and the photon picture of light:
\( K_{\max} = h\nu - \phi_0 = eV_0 \)
(A) For the emission of photo-electrons — this matches (III) The frequency of the incident radiation ν > threshold frequency ν0. A photon can eject an electron only if \( h\nu \ge \phi_0 \); below the threshold frequency there is no emission however intense the light.
(B) Saturation current — this matches (II) depends on the intensity of the incident radiation. The number of photons, and so the number of photoelectrons emitted per second, is proportional to the intensity.
(C) The stopping potential — this matches (IV) measures the maximum kinetic energy of photo-electrons. The stopping potential just stops the fastest electrons, so \( eV_0 = K_{\max} \).
(D) Work function — this matches (I) governs the maximum kinetic energy of emitted photo-electrons for incident radiation of a particular frequency. For a given frequency, \( K_{\max} = h\nu - \phi_0 \), so a metal with a larger work function gives photoelectrons of smaller maximum kinetic energy.
NCERT (2026-27):
Effect of Frequency of Incident Radiation on Stopping Potential – “… (ii) For a given photosensitive material and frequency of incident radiation, saturation current is found to be proportional to the intensity of incident radiation whereas the stopping potential is independent of its intensity (Fig. 11.3). (iii) For a given photosensitive material, there exists a certain minimum cut-off frequency of the incident radiation, called the threshold frequency, below which no emission of photoelectrons takes place, no matter how intense the incident light is.”
Einstein’s Photoelectric Equation: Energy Quantum of Radiation – “… If this quantum of energy absorbed exceeds the minimum energy needed for the electron to escape from the metal surface (work function \( \phi_0 \)), the electron is emitted with maximum kinetic energy
\( \displaystyle K_{max} = h\nu - \phi_0 \qquad (11.2) \)”
Summary – “… The stopping potential is directly related to the maximum kinetic energy of electrons emitted:
\( \displaystyle e V_0 = (1/2)\, m v_{max}^{2} = K_{max} \)”