Maximum kinetic energy of photon is ' $E$ ' when wavelength of incident radiation is ' $\lambda$ '. If wavelength of incident radiations is reduced to $\frac{\lambda}{3}$ then energy of photon becomes four times. Then work function of the metal is

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Aicharya · Accepted Answer

$\mathrm{E}=\frac{\mathrm{hc}}{\lambda}-\phi_0$.... (i) Given: $\lambda=\frac{\lambda}{3}$ and $\mathrm{E}=4 \mathrm{E}$ $\begin{aligned} 4 \mathrm{E} & =\frac{\mathrm{hc}}{\lambda / 3}-\phi_0 .... (ii)\ & =\frac{3 \mathrm{hc}}{\lambda}-\phi_0 \ 4\left(\frac{\mathrm{hc}}{\lambda}-\phi_0ight) & =\frac{3 \mathrm{hc}}{\lambda}-\phi_0 ....(From (i)) \ \frac{4 h \mathrm{c}}{\lambda}-4 \phi_0 & =\frac{3 \mathrm{hc}}{\lambda}-\phi_0 \ \frac{h \mathrm{c}}{\lambda} & =3 \phi_0 \ \phi_0 & =\frac{\mathrm{hc}}{3 \lambda} \end{aligned}$

Maximum kinetic energy of photon is ' $E$ ' when wavelength of incident radiation is ' $\lambda$ '. If…

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