4),
which way would the Lorentz force be for (a) an electron (negative
charge), (b) a proton (positive charge) FIGURE 4 4
Solution   The velocity v of particle is along the x-axis, while B, the
magnetic field is along the y-axis, so v × B is along the z-axis (screw
rule or right-hand thumb rule) So, (a) for electron it will be along –z
axis