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Question
A photon of wavelength 663 nm is incident on a metal surface. The work function of the metal is 1.50 eV. The maximum kinetic energy of the emitted photoelectrons is ______.
Options
3.0 × 10-20 J
6.0 × 10-20 J
4.5 × 10-20 J
9.0 × 10-20 J
Solution
A photon of wavelength 663 nm is incident on a metal surface. The work function of the metal is 1.50 eV. The maximum kinetic energy of the emitted photoelectrons is 6.0 × 10-20 J.
Explanation:
Given: λ = 663 nm, Φ0 = 1.5 eV
To Find: Max kinetic energy
We know that K.E. = `hf - phi_0`
K.E. = `(hc)/lambda - phi_0`
K.E. = `((6.62 xx 10^-34 xx 3 xx 10^8))/((663 xx 10^-9)) - 1.5 xx 1.6 xx 10^-19`
K.E. = `6 xx 10^-20` J
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