#### Transcript Interactions between Electricity and Magnetism

```Interactions between
Electricity and
Magnetism
Interactions between electricity and
magnetism all involve some motion of
either charges (electricity) or changes in
the magnetic field.
Mag/Elec Interactions
 Magnetic Force
 There is a magnetic force whenever a
charge (or charged object) moves across a
magnetic field.
 The Force direction obeys the Right hand
rule we discussed in class.
 The equation for this is F = q v B
 q = amount of charge (C), v = velocity, B =
magnetic field (Teslas)
Magnetic Force on moving
charge
Mag/Elec Interactions
 Right Hand Rule # 1
 Point fingers in direction of moving charge q
 Orient your palm so it’s facing the direction
of the magnetic field B
 Extend your thumb, it’s the direction of the
force.
 This force happens only when the charge
moves perpendicular to the magnetic field B.
Right hand rule for
magnetic force
Mag/Elec Interactions
 A wire carrying a current creates it’s own
magnetic field.
 This field is circular and its orientation is
determined by Right hand rule #2
Mag/Elec Interactions
 Right Hand Rule # 2: to determine the
direction of the circular magnetic field
around a wire carrying a current.
 Direct your thumb along the wire in the
direction of the current.
 Your fingers curl in the direction of the
circular magnetic field
Mag/Elec Interactions
 Electro-magnets
 If you coil a wire into a helical form (like wrapping a
wire around a cylinder) and run a current through it,
each circular coil creates a small mag field.
 The mag field from each coil “adds up” to create
what looks like a magnet with a North and South
pole.
 By running a current through this wire, you “make” a
magnet. This is also known as a solenoid.
```