7. Recall the motor principle. In what three ways can the magnetic force be increased?

6. Green turtles use the earth’s magnetic field to navigate. They seem to use the field to tell them their latitude—how far north or south of the equator they are. Explain how knowing the direction of the earth’s field could give this information.

4. Some pacemakers employ magnetic reed switches to enable doctors to change their mode of operation without surgery. A typical reed switch can be switched from one position to another with a magnetic field of 50 10 4 . × . − T What current must a wire carry if it is to produce a 5 0 10 4 . × − T field at a distance of 0.50 m?

A permanent magnet has field lines as shown below. An electron moves out of the screen toward you at point A. The direction of the magnetic force on the electron is best represented by D 2. 3. 4. 5. 6. zero none of these O 1. O 2. О з. O 5. O 6. 4.

2.How would you orient two long, straight, current carrying wires so that there is no net magnetic force between them?

A 10 m long solenoid contains 284 turns of wire and can generate a magnetic field of 0.01 T from a current of 2.8 A. If the solenoid is broken in half, the field would be expected to... A )Stay the same B Double C)Quarter D) Halve

8. An electron moves at a velocity of 7.24 x 10^6 m/s in a direction perpendicular to a magnetic field of strength 3.77 T. How much force will the electron experience? :   3.06E-12 N   6.12E-12 N   7.43E-12 N   4.37E-12 N

8. Draw the magnetic field lines for the following configurations. Indicate whether the objects experience an attractive or repulsive magnetic force.

1. Describe the direction of the force acting on the charged particle after it enters the magnetic field as shown. ta