An electron having charge \[1.6\times {{10}^{-19}}\,C\] and mass \[9\times {{10}^{-31}}\,kg\] is moving with \[4\times {{10}^{6}}\,m{{s}^{-1}}\] speed in a magnetic field \[2\times {{10}^{-1}}\,tesla\] in a circular orbit. The force acting on electron and the radius of the circular orbit will be [MP PET 1996; JIPMER 2000; BVP 2003]

• A.            \[12.8\times {{10}^{-13}}N,\,1.1\times {{10}^{-4}}m\]
• B.            \[1.28\times {{10}^{-14}}N,\,1.1\times {{10}^{-3}}m\]
• C.            \[1.28\times {{10}^{-13}}N,\,1.1\times {{10}^{-3}}m\]
• D.            \[1.28\times {{10}^{-13}}N,\,1.1\times {{10}^{-4}}m\]