Question

A long straight wire carries a current of 1.5 A. an electron travels with a speed of 5 x 106 cm/s parallel to the wire 10 cm from it and in the same direction as the current. What force does the magnetic field of the current exert on the moving electron.

Answer 1

$$F=eBv=ev\frac{\mu_0 I}{2\pi r}$$

$$F=\frac{(1.6\cdot 10^{-19} \cdot 5\cdot 10^{6} \cdot 4π \cdot10^{-7}\cdot 1.5)}{2π \cdot 0.1}=2.4\cdot 10^{-18} \ N$$