Q18.An electron and proton are separated by a large distance. The electron starts approaching the proton with energy 3 eV . The proton captures the electrons and forms a hydrogen atom in second excited state. The resulting photon is incident on a photosensitive metal of threshold wavelength 4000A What is the maximum kinetic energy of the emitted photoelectron? JEE Main 2021 (27 Jul Shift 2) JEE Main Previous Year Paper (1) 7. 61 eV (2) 1. 41 eV (3) 3. 3 eV (4) No photoelectron would be emitted
What This Question Tests
This complex problem combines concepts from atomic structure (hydrogen energy levels, photon emission) with the photoelectric effect, requiring calculations of photon energy and maximum kinetic energy of photoelectrons.
Concepts Tested
Formulas Used
E_n = -13.6/n² eV
E_photon = E_initial - E_final
K.E._max = E_photon - φ
φ = hc/λ_threshold
📚 NCERT Sections This Tests
12.5 — A Hydrogen Atom Initially In The Ground Level Absorbs A Photon,
Physics Class 12 · Chapter 12
12.5 A hydrogen atom initially in the ground level absorbs a photon, which excites it to the n = 4 level. Determine the wavelength and frequency of photon.
11.8 — Light Of Frequency 7.21 × 1014 Hz Is Incident On A Metal Surface.
Physics Class 12 · Chapter 11
11.8 Light of frequency 7.21 × 1014 Hz is incident on a metal surface. Electrons with a maximum speed of 6.0 × 105 m/s are ejected from the surface. What is the threshold frequency for photoemission of electrons?
11.2 — The Work Function Of Caesium Metal Is 2.14 Ev. When Light Of
Physics Class 12 · Chapter 11
11.2 The work function of caesium metal is 2.14 eV. When light of frequency 6 ×1014Hz is incident on the metal surface, photoemission of electrons occurs. What is the (a) maximum kinetic energy of the emitted electrons, (b) Stopping potential, and (c) maximum speed of the emitted photoelectrons?
📋 Question Details
- Chapter
- Dual Nature of Matter
- Topic
- Photoelectric Effect
- Year
- 2021
- Shift
- 27 Jul Shift 2
- Q Number
- Q18
- Type
- Multi concept
- NCERT Ref
- Class 12 Physics Ch 11: Dual Nature of Radiation and Matter; Class 12 Physics Ch 12: Atoms
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