Q 12-11-022NEETJEE MainEasy
The threshold wavelength of a metal is $620$ nm. Its work function is ($hc = 1240$ eV nm)
Answer: (B) $2$ eV
Concept. $\phi = \dfrac{hc}{\lambda_0}$.
Step 1. Substitute. $\dfrac{1240}{620} = 2$ eV.
Answer. $2$ eV (Option B).
Solution by Sreeraj P, M.Sc Physics