Question 109 of 200
The work functions of cesium (Cs) and lithium (Li) metals are 1.9 eV and 2.5 eV , respectively. If we incident a light of wavelength 550 nm on these two metal surfaces, then photo-electric effect is possible for the case of
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Answer: (C) Cs only
\(E=\frac{1240 \mathrm{eV} \cdot \mathrm{~nm}}{550 \mathrm{~nm}}=2.25 \mathrm{eV}\)
Possible for \(C_s\) as \(E > \phi_{c s}\)
Not for Li as \(E < \phi_{L i}\)
Possible for \(C_s\) as \(E > \phi_{c s}\)
Not for Li as \(E < \phi_{L i}\)