Question: What is the work function of a metal if the threshold frequency is 5 x 10^14 Hz?
Options:
Correct Answer: 3.1 eV
Solution:
The work function φ can be calculated using φ = hf, where h = 6.63 x 10^-34 J.s and f = 5 x 10^14 Hz, giving φ ≈ 3.1 eV.