Interactions between Electricity and Magnetism
Transcript Interactions between Electricity and Magnetism
Interactions between electricity and
magnetism all involve some motion of
either charges (electricity) or changes in
the magnetic field.
There is a magnetic force whenever a
charge (or charged object) moves across a
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
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
This force happens only when the charge
moves perpendicular to the magnetic field B.
Right hand rule for
A wire carrying a current creates it’s own
This field is circular and its orientation is
determined by Right hand rule #2
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
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
By running a current through this wire, you “make” a
magnet. This is also known as a solenoid.