Question 367: Dual Nature of Matter and Radiation

Question

When a photosensitive surface is irradiated by light of wavelengths '$$\lambda_1$$' and '$$\lambda_2$$', kinetic energies of emitted photoelectrons are 'E$$_1$$' and 'E$$_2$$' respectively. The work function of photosensitive surface is

Accepted Answer

$$\mathrm{E}_1=\frac{\mathrm{hc}}{\lambda_1}-\mathrm{W} \quad 	herefore \mathrm{E}_1 \lambda_1=\mathrm{hc}-\mathrm{W} \lambda_1$$
$$\mathrm{E}_2=\frac{\mathrm{hc}}{\lambda_2}-\mathrm{W} \quad 	herefore \mathrm{hc}=\mathrm{E}_1 \lambda_1+\mathrm{W} \lambda_1$$ ...... (i)
$$	herefore \mathrm{E}_2 \lambda_2=\mathrm{hc}-\mathrm{W}_2 \quad 	herefore \mathrm{hc}=\mathrm{E}_2 \lambda_2+\mathrm{W} \lambda_2$$ ....... (ii)
By Eq.(i) and (ii)
$$\mathrm{E_1 \lambda_1+W \lambda_1=E_2 \lambda_2+\mathrm{W} \lambda_2}$$
$$	herefore \mathrm{E}_1 \lambda_1-\mathrm{E}_2 \lambda_2=\mathrm{W}\left(\lambda_2-\lambda_1ight)$$
$$	herefore \mathrm{W}=\frac{\mathrm{E}_1 \lambda_1-\mathrm{E}_2 \lambda_2}{\lambda_2-\lambda_1}$$

Answer

$$\frac{\left(\lambda_1 E_1-\lambda_2 E_2\right)}{\left(\lambda_2-\lambda_1\right)}$$

Answer

$$\frac{\left(\lambda_1 \mathrm{E}_1+\lambda_2 \mathrm{E}_2\right)}{\left(\lambda_2-\lambda_1\right)}$$

Answer

$$\frac{\left(\lambda_1 \mathrm{E}_2-\lambda_2 \mathrm{E}_1\right)}{\left(\lambda_2-\lambda_1\right)}$$

Answer

$$\frac{\left(\lambda_1 E_2+\lambda_2 E_1\right)}{\left(\lambda_2-\lambda_1\right)}$$

Dual Nature of Matter and Radiation

When a photosensitive surface is irradiated by light of wavelengths '$\lambda_1' and '\lambda_2', kinetic energies of emitted photoelectrons are 'E_1' and 'E_2$' respectively. The work function of photosensitive surface is

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