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Ejection of the photoelectron from metal in the photoelectric effect experiment can be stopped by applying 0.5 V when radiation of 250 nm is used. The work function of the metal is : [JEE-Main On line-2018]

1. 4 eV
2. 5.5 eV
3. 4.5 eV
4. 5 eV

Correct answer: 5.5 eV

Solution

The work function of the metal can be calculated using the energy of the incident photons and the stopping potential. The energy of the photons at 250 nm is approximately 4.97 eV, and since a stopping potential of 0.5 V is needed, the work function must be the photon energy minus the stopping potential, resulting in a work function of 5.5 eV.

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