Physics · 2021
JEE Main · 17 March 2021, Shift 2 · Q14
Two identical photocathodes receive the light of frequencies f_1 and f_2 respectively. If the velocities of the photo-electrons coming out are v_1…
Two identical photocathodes receive the light of frequencies $\displaystyle f_1$ and $\displaystyle f_2$ respectively. If the velocities of the photo-electrons coming out are $\displaystyle v_1$ and $\displaystyle v_2$ respectively, then
Official answer
(2)
$\displaystyle v_1^2-v_2^2=\frac{2 \mathrm{~h}}{\mathrm{~m}}\left[f_1-f_2\right]$
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JEE Main 2021 Physics question, with the answer from NTA’s final answer key. Where our answers come from.