A magnetic field of 5×10−4T just balances a perpendicular electric field of 15 kV/m in their effect on an electron beam passing through the two fields in a direction perpendicular to both of them. What is the speed of the electrons?
Answer & explanation
Correct answer: option 3
v = \(\frac{E}{B}\) = \(\frac{15 x 10^{3}}{5 x 10^{-4}}\)
= 3×107 m/s