Photons of energy 7 eV fall on a metal of work function 2.5 eV. What is the maximum kinetic energy of the emitted photoelectrons?
Answer and explanation
Correct answer: B. 4.5 eV
- Step 1: Einstein's equation gives eV. Answer: 4.5 eV. Why not the others: 9.5 eV: adds the work function. 2.5 eV: gives the work function itself. 7 eV: ignores the work function.
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