1. Magnetic Force/Field

2. Magnetic Field North/South Pole Opposites attract Unit: Tesla (T) Field lines point in direction that a North Pole would feel a force

3. Earth behaves magnetically as if a bar magnet was located near its center

4. Magnetic Force on a moving Charge 1. Charge must be moving 2. Velocity must have a component perpendicular to the direction of the magnetic field Direction of Force is perpendicular to both velocity and field RHR #1 Fingers = B Field Thumb = velocity or current Palm = Force

5. Why? (such a weird direction)

6. What happens near the poles where the charges are not deflected ?

7. Force on a moving Charge F = B * q o (v sin θ) (N) What is the force on a 2μC charge moving at 4.3x10 4 m/s perpendicular to a 0.4 T magnetic field?

8. A proton (m= 1.67x10 -27 kg, q= 1.6x10 -19 C) is moving with a velocity, v= 6.3x10 -5 m/s, and enters a region with a magnetic field of 0.4 T. What is the radius of the circle that the charge will move through? What is the final velocity of the charge?

9. Force on a current in a wire: F = I l B sin(θ) A square loop (10cm) of wire has a current of 5A flowing clockwise and is placed in a 0.4T magnetic field directed into the page. What is the magnitude and direction of the force on each segment of the loop? X X X X X X

10. Torque on a loop:  N I A B sin(φ) A square loop (10cm) of wire has a current of 2A flowing clockwise and is placed in a 0.75T magnetic field directed to the right. What is the magnitude and direction of the torque on the loop?

11. A square loop (10cm) of wire has a current of 2A flowing clockwise and is placed in a 0.75T magnetic field as shown below. What is the magnitude and direction of the torque on the loop? Top view 60 o