When light of wavelength 248 nm falls on a metal of threshold energy 3.0 eV, the de-Broglie wavelength of emitted electrons is \ \ \ \ Å. (Round off…

When light of wavelength $\displaystyle 248$ nm falls on a metal of threshold energy $\displaystyle 3.0$ eV, the de-Broglie wavelength of emitted electrons is \_\_\_\_ Å. (Round off to the Nearest Integer). [Use : $\displaystyle \sqrt{3}=1.73, \mathrm{~h}=6.63 \times 10^{-34} \mathrm{~Js}$ $$\left.\mathrm{m}_{\mathrm{e}}=9.1 \times 10^{-31} \mathrm{~kg} ; \mathrm{c}=3.0 \times 10^8 \mathrm{~ms}^{-1} ; 1 \mathrm{eV}=1.6 \times 10^{-19} \mathrm{~J}\right] $$