Some laws / processes are given in Column I. Match these with the physical phenomena given in Column II and indicate your answer by darkening appropriate bubbles in the 4 × 4 matrix given in the ORS.
| Column I | Column II |
|---|---|
| (A) Transition between two atomic energy levels | (p) Characteristic X-rays |
| (B) Electron emission from a material | (q) Photoelectric effect |
| (C) Mosley's law | (r) Hydrogen spectrum |
| (D) Change of photon energy into kinetic energy of electrons | (s) - decay |
Answer: A → I, A → III, B → II, B → IV, C → I, D → II
Solution
(A) Transition between two atomic energy levels: This produces photons with specific energies. In hydrogen, this gives the hydrogen spectrum. In heavier atoms, inner-shell transitions produce characteristic X-rays. Matches (p) and (r).
(B) Electron emission from a material: This occurs in the photoelectric effect (photon ejects electron) and in β-decay (nucleus emits electron). Matches (q) and (s).
(C) Mosley's law: This relates the frequency of characteristic X-rays to the atomic number of the target element. Matches (p) only.
(D) Change of photon energy into kinetic energy of electrons: This is the photoelectric effect, where a photon's energy is transferred to an electron. Matches (q) only.
Pairs: A→(p),(r); B→(q),(s); C→(p); D→(q).
(B) Electron emission from a material: This occurs in the photoelectric effect (photon ejects electron) and in β-decay (nucleus emits electron). Matches (q) and (s).
(C) Mosley's law: This relates the frequency of characteristic X-rays to the atomic number of the target element. Matches (p) only.
(D) Change of photon energy into kinetic energy of electrons: This is the photoelectric effect, where a photon's energy is transferred to an electron. Matches (q) only.
Pairs: A→(p),(r); B→(q),(s); C→(p); D→(q).
JEE Advanced · 2007 · 08 Apr 2007 · Paper 1 · Match the columns