question_answer

In a Thomson set-up for the determination of e/m, electrons accelerated by 2.5 \[kV\] enter the region of crossed electric and magnetic fields of strengths \[3.6\times {{10}^{4}}V{{m}^{-1}}\] and \[1.2\times {{10}^{-3}}T\] respectively and go through undeflected. The measured value of \[e/m\] of the electron is equal to                 [AMU 2002]

A)            \[1.0\times {{10}^{11}}C\text{-}k{{g}^{-1}}\]             

B)            \[1.76\times {{10}^{11}}C\text{-}k{{g}^{-1}}\]

C)            \[1.80\times {{10}^{11}}C\text{-}k{{g}^{-1}}\]          

D)            \[1.85\times {{10}^{11}}C\text{-}k{{g}^{-1}}\]