A light of wavelength 500 nm falls on a metal surface, whose work function is 2.14 eV, The kinetic energy of the emitted electrons is |
3.4 eV 0.34 eV 2.48 eV 0.034 eV |
0.34 eV |
The correct answer is Option (2) → 0.34 eV Given: Wavelength, $\lambda = 500 \, \text{nm} = 500 \times 10^{-9} \, \text{m}$ Work function, $\phi = 2.14 \, \text{eV}$ Energy of incident photon: $E = \frac{hc}{\lambda}$ $E = \frac{(6.63 \times 10^{-34})(3 \times 10^8)}{500 \times 10^{-9}}$ $E = 3.978 \times 10^{-19} \, \text{J}$ Convert to eV: $E = \frac{3.978 \times 10^{-19}}{1.6 \times 10^{-19}} = 2.486 \, \text{eV}$ Kinetic energy of emitted electrons: $K = E - \phi = 2.486 - 2.14 = 0.346 \, \text{eV}$ Final Answer: $K = 0.35 \, \text{eV}$ |