Q 12-11-103JEE MainJEE Main 2022 (24 Jun, Shift 2)Easy
Light of two different frequencies whose photons have energies $3.8\ \text{eV}$ and $1.4\ \text{eV}$ respectively illuminate a metallic surface whose work function is $0.6\ \text{eV}$ successively. The ratio of maximum speeds of emitted electrons for the two frequencies respectively will be:
Answer: (A) $2 : 1$
Maximum kinetic energies: $3.8 - 0.6 = 3.2\ \text{eV}$ and $1.4 - 0.6 = 0.8\ \text{eV}$.
$$\frac{v_1}{v_2} = \sqrt{\frac{3.2}{0.8}} = 2$$
Solution by Sreeraj P, M.Sc Physics