Transcript Interactions between Electricity and Magnetism Notes

Interactions between
Electricity and
Magnetism
Interactions between electricity and
magnetism all involve some motion of
either charges (electricity) or changes in
the magnetic field.
Magnetic Force
 Magnetic Force
 There is a magnetic force whenever a
charge (or charged object) moves across a
magnetic field.
 The equation for this is F = q v B
 q = amount of charge (C)
 v = velocity
 B = magnetic field (Teslas)
Right Hand Rule #1
 Extend your thumb, it’s the direction of the
current.
 Point fingers in direction of the Magnetic
Field, B. (Fingers = field lines)
 Orient your palm so it’s the direction of the
force (Palm Push)
 This force happens only when the charge
moves perpendicular to the magnetic field B.
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.