Q 12-11-074JEE MainJEE Main 2024 (30 Jan, Shift 1)Easy
The work function of a substance is $3.0\ \text{eV}$. The longest wavelength of light that can cause the emission of photoelectrons from this substance is approximately:
Answer: (B) $414\ \text{nm}$
$$\lambda_{max} = \frac{hc}{\phi} = \frac{1240\ \text{eV nm}}{3.0\ \text{eV}} \approx 414\ \text{nm}$$
Solution by Sreeraj P, M.Sc Physics