Question

A very long, straight wire carries a current of 20.0 A in the +k direction. An electron 0.8 cm from the center of the wire in the i direction is moving with a speed of 6.82 106 m/s. Find the force on the electron when it moves in the following directions.

(a) directly away from the wire

(b) parallel to the wire in the direction of the current

(c) perpendicular to the wire and tangent to a circle around the wire in the + j direction

Answer 1

the magnetic field due to the current carrying conductor is

The force on the electron is given as

a) for the first case, the electron moves in x direction (away from wire) and field is along -y direction

The force is along z axis.

b) in this case the electron is moving in k direction and field is also along - y direction, then

The force is along negative x axis

c) In this case the cross product result to zero force as the field and speed are along the negative y axis.

F =