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प्रश्न
If light of wavelength 412.5 nm is incident on each of the metals given below, which ones will show photoelectric emission and why?
| Metal | Work Function (eV) |
| Na | 1.92 |
| K | 2.15 |
| Ca | 3.20 |
| Mo | 4.17 |
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उत्तर
Energy of a photon of the given light is, E = `1240/lambda = 3 ev`
Thus, metals having work-function less than energy of photon of falling light will show photoelectric effect. So, Na and K will show photoelectric effect.
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