A) \[2900\text{ }\overset{o}{\mathop{\text{A}}}\,\]
B) \[\text{2500 }\overset{o}{\mathop{\text{A}}}\,\]
C) \[\text{5380 }\overset{o}{\mathop{\text{A}}}\,\]
D) \[\text{1200 }\overset{o}{\mathop{\text{A}}}\,\]
Correct Answer: C
Solution :
Here, work function \[{{W}_{0}}=2.3\text{ }eV=2.3\times 1.6\times {{10}^{-19}}J\] where,\[{{\lambda }_{0}}\]is the threshold wavelength for sodium. Then, \[{{W}_{0}}=\frac{hc}{{{\lambda }_{0}}}\]or \[{{\lambda }_{0}}=\frac{hc}{{{W}_{0}}}\] \[{{\lambda }_{0}}=\frac{6.6\times {{10}^{-34}}\times 3\times {{10}^{8}}}{2.3\times 1.6\times {{10}^{-19}}}\] \[=5380\times {{10}^{-10}}m\] \[=5380\,\overset{o}{\mathop{\text{A}}}\,\]You need to login to perform this action.
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