At threshold: hc/λ₀ = φ. So λ₀ = hc/φ = 1240/4.2 ≈ 295 nm
Back to JEE Main 2023 Modern Physics
JEE Main 2023 — Physics Modern Physics
medium
mcq
2023
Official previous-year question
Verified 30 May 2026.
Question
The work function of a metal is 4.2 eV. The threshold wavelength is (hc = 1240 eV·nm):
Options
- A295 nm
- B300 nm
- C310 nm
- D325 nm
Solution
Did you get this right?
Sign in to track your attempts and accuracy.
Your note
Sign in to keep a private note on this question. Nothing you write is ever public.
JEE Main Modern Physics in other years
More JEE Main Modern Physics Questions
The work function of a metal is 4.2 eV. The threshold wavelength for photoelectric emission is approximately:
2026
medium
mcq
The de Broglie wavelength of a particle with mass m and velocity v is:
2025
hard
mcq
The work function of a metal is 4.2 eV. What is the threshold wavelength for photoelectric emission? (hc = 1240 eV·nm)
2025
medium
mcq
In Bohrs model the ratio of the kinetic energy to the total energy of the electron in nth orbit is:
2023
hard
mcq
In hydrogen atom, the ratio of radii of first and second orbit is:
2022
easy
mcq