28 13

1
(28 13)
2
(28 14)
3
(28 15)
4
(28 16)
5
(28 17)
6
hitt

• A proton undergoes a circular motion at a speed
  of 4 106 m/s in a uniform magnetic field of 4
  T. What is the period of the motion?
• A. 16 ns B. 32 ns C. 8.9 ps D. 18 ps
• E. 27 ps.

7
Phy 2049 Magnetism etc.

• Magnetic fields and magnetic forces
• Torque on a current loop
• Hall effect
• Magnetic field produced by currents
• Biot-Savart Law
• Ampere law
• Force between two current carrying wires.

8
Chapter 29 Magnetic Fields Due to
Currents
In this chapter we will explore the
relationship between an electric current and the
magnetic field it generates in the space around
it. We will follow a two-prong approach,
depending on the symmetry of the problem.

For
problems with low symmetry we will use the law of
Biot-Savart in combination with the principle of
superposition.
For problems with high symmetry
we will introduce Amperes law. Both
approaches will be used to explore the magnetic
field generated by currents in a variety of
geometries (straight wire, wire loop, solenoid
coil, toroid coil)

We will also determine the force between two
parallel current carrying conductors. We will
then use this force to define the SI unit for
electric current (the Ampere)
(29 1)
9
(29 2)
10
(29 3)
11
(29 4)
12
(29 5)
13
(29 6)
14
(29 7)
15
(29 8)
16
(29 9)
17
(29 10)
18
(29 11)
19
(29 12)
20
(29 13)
21
(29 14)
22
hitt

• A proton undergoes a circular motion at a speed
  of 4 106 m/s in a uniform magnetic field of 4
  T. What is the radius of the circular motion?
• A. 0.066 m B. 0.01 m C. 5.7 µm D. 12 µm
• E. 0.13 m.