Match List-I (modern physics concept) with List-II (associated term):
| List-I | List-II |
|---|---|
| I. De Broglie hypothesis | 1. γ → e⁻ + e⁺ |
| II. Compton effect | 2. Splitting of spectral lines |
| III. Zeeman effect | 3. Matter waves |
| IV. Pair production | 4. Photon scattering |
Codes (in the order I II III IV):
- A1, 2, 3, 4
- B2, 1, 4, 3
- C3, 4, 2, 1
- D4, 1, 2, 3
Show answer and explanation
Correct answer: (c) 3, 4, 2, 1
Explanation
- I. De Broglie hypothesis → 3, matter waves: moving particles such as electrons have a wavelength λ = h/p.
- II. Compton effect → 4, photon scattering: X-ray photons scattered by electrons come out with a longer wavelength, which shows that light carries momentum like a particle.
- III. Zeeman effect → 2, splitting of spectral lines when atoms are placed in a magnetic field.
- IV. Pair production → 1, γ → e⁻ + e⁺: a high-energy gamma photon near a nucleus turns into an electron and a positron. It needs at least 1.02 MeV.
So the code is 3, 4, 2, 1.