In: Physics
5. An electron moves to the right, entering a region that has a uniform electric field directed at you. The direction of the force perceived by the electron is:
a. down
b. up
c. on the right
d. towards you
e. None of the above
Force on a moving charge due to magnetic field is given by: q x, where q is charge, is velocity vector and is magnetic field vector.
Since cross product is involved, direction of force is given by right hand thumb rule. According to right hand thumb rule, cross product x is given by the direction of your thumb, when your fingers curl from to .
Here, is towards right and is towards you. So,x is downwards(according to right hand rule).
Now, q is negative(charge on electron is negative). So, force = q x is towards up(option b).