MDCAT Physics MCQ #2560

The minimum energy required to eject an electron from a metal surface is 4.5 eV. What is the maximum wavelength of light that can eject an electron?

MDCAT Physics MCQ #2560

  1. Question 1

    Q1. The minimum energy required to eject an electron from a metal surface is 4.5 eV. What is the maximum wavelength of light that can eject an electron?

    • A) 275 nm
    • B) 300 nm
    • C) 250 nm
    • D) 325 nm

    Answer: 275 nm

    Explanation: λ = hc/E = (6.63×10^-34 × 3×10^8)/(4.5 × 1.6×10^-19) = 275 nm. Other options miscalculate or use wrong units.