A photon of energy 2.5 eV and wavelength λ falls on a metal surface and the ejected electrons have velocity v. If the λ of the incident light is decreased by 20%, the maximum velocity of the emitted electrons is doubled. The work function of the metal is

Question

A photon of energy 2.5 eV and wavelength λ falls on a metal surface and the ejected electrons have velocity v. If the λ of the incident light is decreased by 20%, the maximum velocity of the emitted electrons is doubled. The work function of the metal is (A) 2.6 eV (B) 2.23 eV. (C) 2.5 eV (D) 2.29 eV

Tardigrade Admin · Accepted Answer

(ν21/ν22) = ((hc/λ1) - ω/(hc)λ2 - ω) use E = (12400/λ(A0))

Q. A photon of energy 2.5 eV and wavelength $λ$ falls on a metal surface and the ejected electrons have velocity v. If the $λ$ of the incident light is decreased by 20%, the maximum velocity of the emitted electrons is doubled. The work function of the metal is

2.6 eV

2.23 eV.

2.5 eV

2.29 eV

$\frac{ν _{1}^{2}}{ν _{2}^{2}} = \frac{\frac{h c}{λ _{1}} - ω}{\frac{h c}{λ _{2}} - ω}$
use $E = \frac{12400}{λ ( A ^{0} )}$

Q. A photon of energy 2.5 eV and wavelength λ falls on a metal surface and the ejected electrons have velocity v. If the λ of the incident light is decreased by 20%, the maximum velocity of the emitted electrons is doubled. The work function of the metal is