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Physics · PYQ NEET UG 2019(2)
हिन्दीThe work function of a photosensitive material is \( 4.0 \text{ eV} \). The longest wavelength of light that can cause photon emission from the substance is (approximately)
Correct answer · Option 1
\( 310 \text{ nm} \)
Explanation
Threshold wavelength \( \lambda_0 = \frac{hc}{\phi} = \frac{12400 \text{ eV }\text{\AA}}{4.0 \text{ eV}} = 3100 \text{ \AA} = 310 \text{ nm} \).
