Fundamentholfundamenthol

JEE Main 2025 Jan 22 Shift 1, Physics Q14: Introduction and Photoelectric Effect

JEE Main2025Jan 22, Shift 1Physics
Q.

The work functions of cesium (Cs) and lithium (Li) metals are 1.9 eV and 2.5 eV, respectively. If we incident a light of wavelength 550 nm on these two metal surface, then photo-electric effect is possible for the case of

  1. A

    Li only

  2. B

    Cs only

  3. C

    Neither Cs nor Li

  4. D

    Both Cs and Li

Solution

Photon energy: eV eV.

Photoemission requires .

For Cs: eV eV emission occurs.

For Li: eV eV no emission.

Photoelectric effect is possible only for Cs.

Concept behind this question

Introduction and Photoelectric EffectNotes, formulas and examples →

More previous year questions on Introduction and Photoelectric Effect

Practice more Physics

Concept-wise practice with instant solutions on Fundamenthol.

Start practicing →