1. Magnetism Magnetic Field
Magnetism is a force of ___________ or ___________ that acts at a distance and is due to a _____________ field.
Magnetic fields are caused by _____________ electrically charged particles.
attraction
repulsion
magnetic
moving
Magnetic Field
Just like electric fields, magnetic fields are represented by _________.
Magnetic fields originate on _______ _________ and terminate on _______ _________ .
Unlike electric charges, magnetic poles cannot be ___________.
arrows
north
poles
south
poles
isolated

2. µo I B = 2r Magnetic field around a current carrying wire
Magnetic fields are caused by _____________ electrically charged particles. Thus any wire carrying _______________ will induce a __________ ________ around the wire. The shape of the magnetic field is ___________ __________.
moving
current
magnetic
field
concentric
circles
Magnitude of the magnetic field around a current carrying wire
µo I B =
2r
Where:
B =
magnetic field strength (Tesla)
µo =
4π x 10-7 T.m/A
I =
current (amperes)
r =
distance from the wire (meters)

3. Direction of the magnetic field around a current carrying wire
Right Hand Rule I
Thumb -
points in direction of conventional current
encompass the wire in the direction of the magnetic field
Fingers -
* The Right-Hand Rules apply to positive
charges or positive (conventional) current

4. F = qvB Forces on moving charges
When a charge is placed in an ____________ ___________
________, that charge will experience a ____________ _________
if two conditions are met.
external
magnetic
field
magnetic
force 1)
the charge is moving relative to the magnetic field, 2)
the charge's velocity has a component perpendicular
to the direction of the magnetic field
Magnitude of the force on a moving electric charge
F =
magnetic Force (N)
F = qvB
Where:
q =
electric charge (C)
v =
velocity of charge (m/s)
B =
EXTERNAL magnetic field (T)

5. F = Il B l = Magnitude of the force on a current-carrying wire
magnetic Force (N)
F = Il B
Where:
I =
current (A)
l =
wire length (m)
B =
EXTERNAL magnetic field (T)
Direction of the force on a moving charge or a current- carrying wire
Right Hand Rule II
Thumb -
points in direction of conventional current
points in the direction of the external magnetic field
Fingers -
Palm -
points in the direction of the force I

6. Practice RHR I P Direction of B field? (a) I (b)
Direction of B field at point P? B
out of the page I
(d) P
Will wires attract or repel?
(c)
attract
The field at point P is into the page, what direction is the current? I I

7. Practice RHR II - B N S In what direction is the proton deflected?
X X X X X X X X
N S
In what direction is the proton deflected?
out of the page +
The wire is pulled down, which way is current induced? B
left B
O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O -
In what direction is the electron deflected?
Which direction will the wire move?
out of the page
left

8. Try this mv r = qB B X X X X X X X X Where:
In what direction is the charge initially forced when entering the field? B
X X X X X X X X
right
What happens to the path of the charge as it moves through the field? mv r = qB
It curves -
Where:
v =
velocity of charge (m/s)
q =
charge (C)
r =
radius of curved path (meters)
m =
mass of charge (kg)
B =
EXTERNAL magnetic field (T)