In photoelectric effect an EM-wave is incident on a metal surface and electrons are ejected from the surface. If the wor…
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In photoelectric effect an EM-wave is incident on a metal surface and electrons are ejected from the surface. If the work function of the metal is 2.14 eV and stopping potential is 2 V , what is the wavelength of the EM-wave ?
(Given \(\mathrm{hc}=1242\mathrm{eVnm}\) where h is the Planck's constant and c is the speed of light in vaccum.)
[JEE Main 2025, 23 Jan (Shift 2)]
✓ Correct answer: a)
300 nm
Explanation
\(K\cdot E=e{V}_{s}\\ =2eV\\ K\cdot E\cdot =E-∅\\ 2=E-2.14\\ E=4.14eV\\ \frac{hc}{\lambda }=E\\ \frac{1242}{\lambda }=4.14\)
\(\lambda =300nm\)
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