Q45.In photoelectric effect an em-wave is incident on a metal surface and electrons are ejected from the surface. If the work function of the metal is 2.14 eV and stopping potential is 2 V , what is the wavelength of the em- wave ? (Given hc = 1242eVnm where h is the Planck's constant and c is the speed of light in vaccum.) 2025 (23 Jan Shift 2) JEE Main Previous Year Paper (1) 300 nm (2) 400 nm (3) 600 nm (4) 200 nm
What This Question Tests
This question is a straightforward application of Einstein's photoelectric equation, relating the maximum kinetic energy of emitted electrons to work function and incident photon energy. It tests the ability to calculate the wavelength of an EM wave given stopping potential and work function.
Concepts Tested
Formulas Used
Kmax = eVs
Kmax = hν - φ
hν = hc/λ
📚 NCERT Sections This Tests
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?
11.7 — The Work Function For A Certain Metal Is 4.2 Ev. Will This Metal Give
Physics Class 12 · Chapter 11
11.7 The work function for a certain metal is 4.2 eV. Will this metal give hotoelectric emission for incident radiation of wavelength 330 nm?
11.9 — Light Of Wavelength 488 Nm Is Produced By An Argon Laser Which Is
Physics Class 12 · Chapter 11
11.9 Light of wavelength 488 nm is produced by an argon laser which is used in the photoelectric effect. When light from this spectral line is incident on the emitter, the stopping (cut-off) potential of photoelectrons is 0.38 V. Find the work function of the material from which the emitter is made.
📋 Question Details
- Chapter
- Dual Nature of Matter
- Topic
- Photoelectric Effect
- Year
- 2025
- Shift
- 23 Jan Shift 2
- Q Number
- Q45
- Type
- MCQ
- NCERT Ref
- Class 12 Physics Ch 11: Dual Nature of Radiation and Matter
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