If λ∘ & beλ threshold wavelength & wavelength of incident light, the velocity of photo electron ejected from the metal Surface is

A
$\sqrt{\frac{2 h}{m} (λ_{\circ} - λ)}$
B
$\sqrt{\frac{2 hc}{m} (λ_{\circ} - λ)}$
C
$\sqrt{\frac{2 hc}{m} (\frac{λ_{\circ} - λ}{{λλ}_{\circ}})}$
D
$\sqrt{\frac{2 h}{m} (\frac{1}{λ_{\circ}} - \frac{1}{λ})}$

Solution:

48. K.E of the ejected electron is given by equation $hυ = {hυ}_{0} + \frac{1}{2} {mv}^{2}$
$\frac{1}{2} {mv}^{2} = \frac{hc}{λ} - \frac{hc}{λ_{0}} = hc (\frac{λ_{0} - λ}{{λλ}_{0}})$ $v = \sqrt{\frac{2 hc}{m} (\frac{λ_{0} - λ}{λ_{0} λ})}$

If $λ_{\circ}$ & be $λ$ threshold wavelength & wavelength of incident light, the velocity of photo electron ejected from the metal Surface is

Solution:

Related content