Magnetic Fields
1. An electron gun fires electrons into a magnetic field directed straight downward. Find the direction of the force exerted by the field on an electron for each of the following directions of the electron’s velocity: (a) horizontal and due north; (b) horizontal and 30° west of north; (c) due north, but at 30° below the horizontal; (d) straight upward.
2. (a) Find the direction of the force on a proton moving through the magnetic fields in Figure 1, as shown. (b) Repeat part (a), assuming the moving particle is an electron.
[pic]
Figure 1
3. Find the direction of the magnetic field acting on the positively charged particle moving in the various situations shown in Figure 2 if the direction of the magnetic force acting on it is as indicated.
[pic] Figure 2
4. The magnetic field of the Earth at a certain location is directed vertically downward and has a magnitude of 50.0 μT. A proton is moving horizontally toward the west in this field with a speed of 6.20 × 106 m/s. What are the direction and magnitude of the magnetic force the field exerts on the proton?
Magnetic Force on a Current-Carrying Conductor
5. A current I = 15 A is directed along the positive x-axis and perpendicular to a magnetic field. A magnetic force per unit length of 0.12 N/m acts on the conductor in the negative y-direction. Calculate the magnitude and direction of the magnetic field in the region through which the current passes.
6. In Figure 1, assume that in each case the velocity vector shown is replaced with a wire carrying a current in the direction of the velocity vector. For each case, find the direction of the magnetic force acting on the wire.
7. In Figure 2, assume that in each case the velocity vector shown is replaced with a wire carrying a current in the direction of the velocity vector. For each case, find the direction of the magnetic field that will produce the