In a photoelectric effect experiment, the work function of a metal is 2.0 eV. When light of photon energy 4.0 eV strikes the metal, what is the maximum kinetic energy of the emitted photoelectrons?
Show the answer and explanation
Correct answer
B. 2.0 eV
Principle or equation
Einstein's photoelectric equation: K_max = hf - W, where hf is the photon energy and W is the work function.
Why this answer is correct
K_max = 4.0 eV - 2.0 eV = 2.0 eV.
Example
If photon energy is 5 eV and work function is 3 eV, K_max = 2 eV.
This published item includes a stored explanation and passed the platform’s publication workflow. It is independent preparation material, not a claim of an official or recalled examination question.