Consider a wire carrying a current I in a field of flux density B

(Figure 1). We have

I= nAve = qAv where q = ne also I = q/t and F= BILsinq

Therefore the force on a charge q is:

If the charge moves at right angles to the magnetic field this becomes

For an electron (charge e) moving at right angles to the field the formula is:

Notice that if the charge is at rest there is no force upon it due to the magnetic field

Calculate the force on an alpha particle moving with a velocity of 2x10

Force = Bqv sinq = 3x10