question_answer

A beam of electrons is moving with constant velocity in a region having electric and magnetic fields of strength \[20V{{m}^{-1}}\]and 0.5 T at right angles to the direction of motion of the electrons. What is the velocity of the electrons?

A)  20 \[m{{s}^{-1}}\]          

B)  40 \[m{{s}^{-1}}\]

C)  8 \[m{{s}^{-1}}\]             

D)  5.5 \[m{{s}^{-1}}\]