Question

In a photoelectric experiment with a material of work function 2.1 eV, the stopping potential is found to be 2.5 V. The maximum kinetic energy of ejected photoelectrons is:

• A. 0.4 eV
• B. 2.1 eV
• C. 2.5 eV
• D. 4.6 eV

Hint:

The stopping potential is the minimum voltage required to stop the most energetic photoelectrons, and it directly measures their maximum kinetic energy.

Answer 1

The Correct Option is C

The maximum kinetic energy \( K_{\text{max}} \) of the ejected photoelectrons is given by: \[ K_{\text{max}} = e V_s \] where \( V_s \) is the stopping potential. Given \( V_s = 2.5 \, \text{V} \): \[ K_{\text{max}} = 2.5 \, \text{eV} \] Thus, the correct answer is (C).