Work function of a photosensitive material is 6.2 eV. Incident radiation produces a stopping potential of 5 V. Its wavelength lies in:
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Question

Work function of a photosensitive material is 6.2 eV. Incident radiation produces a stopping potential of 5 V. Its wavelength lies in:

G1 Physics · Accepted Answer

Photon energy E = W + eV₀ = 6.2 + 5 = 11.2 eV. Wavelength λ = 1240/11.2 ≈ 111 nm, which belongs to the ultraviolet region. Answer: A.