question_answer

The energy of an X- ray photon of wavelength 1.65 Å is \[(h=6.6\times {{10}^{-34}}J\text{-}sec,\,\,c=3\times {{10}^{8}}m{{s}^{-1}}\], \[1eV=1.6\times {{10}^{-19}}J)\] [EAMCET (Engg.) 2000]

A)             3.5 keV                                  

B)            5.5 keV

C)            7.5 keV                                   

D)            9.5 keV