A velocity selector consists of electric and magnetic fields described by the expressions vector E = E k hat bold and vector B = B j hat bold, with B = 0.0140 T. Find the value of E such that a 670 -eV electron moving along the negative x axis is undeflected.

Question

A velocity selector consists of electric and magnetic fields described by the expressions vector E  = E k hat bold and vector B  = B j hat bold, with B = 0.0140 T. Find the value of E such that a 670 -eV electron moving along the negative x axis is undeflected.

bobpursley · Answer

get the force from qBxV, then set it equal to Eq. Yes, you will have to calculate velocity from the energy given.