MCQ
When a metal is irradiated by light having wavelength $\lambda (\lambda < \lambda_0)$, all the photoelectron emitted are bent in a circle of radius $r$ by a magnetic of flux density $B_0$. Find the $\frac{1}{\lambda_0}$ where $\lambda_0$ is thershold wavelength.
- ✓$\frac{1}{{{\lambda _0}}} = \frac{1}{\lambda } - \frac{{{B^2}{e^2}{r^2}}}{{2mhc}}$
- B$\frac{1}{{{\lambda _0}}} = \frac{1}{\lambda } + \frac{{{B^2}{e^2}{r^2}}}{{2mhc}}$
- C$\frac{1}{{{\lambda _0}}} = \frac{1}{\lambda } - \frac{{{B^2}{e^2}{r^2}}}{{mhc}}$
- DNone of these
