A) \[0.62\overset{\text{o}}{\mathop{\text{A}}}\,\]
B) \[2.48\overset{\text{o}}{\mathop{\text{A}}}\,\]
C) \[0.124\overset{\text{o}}{\mathop{\text{A}}}\,\]
D) \[1.24\overset{\text{o}}{\mathop{\text{A}}}\,\]
Correct Answer: D
Solution :
From Einsteins photoelectric equation, we have \[E=hv=\frac{hc}{\lambda }\]where h is Plancks constant, c the speed of light and \[\lambda \] the wavelength. Given, \[E=10\,kV=10\times {{10}^{3}}V\], \[E=1.6\times {{10}^{-19}}\times 10\times {{10}^{3}}J\] \[=1.6\times {{10}^{-15}}J\] \[h=6.6\times {{10}^{-34}}J-s\], \[c=3\times {{10}^{8}}m/s\] \[\Rightarrow \] \[\lambda =\frac{hc}{E}=\frac{6.6\times {{10}^{-34}}\times 3\times {{10}^{8}}}{1.6\times {{10}^{-15}}}\] \[\Rightarrow \] \[\lambda =1.24\times {{10}^{-10}}m\] \[\Rightarrow \] \[\lambda =1.24\,\overset{o}{\mathop{A}}\,\]You need to login to perform this action.
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