Magnetic Field Around a Loop of Wire

"My Magnet Attracting Money"

'Did you know that US currency is attracted to a magnet? There are iron particles in the ink that is causes this attraction.' Rob Gallagher - Rob the 'MagnetNerd'

Making a Magnet
with Electricity

Electric Magnets are created using
thousands of wire loops

We can understand an electric magnet
 by understanding the magnetism
of a single loop of wire

Ex 3) Magnetic field around a Single Loop of Wire w/ current

[ Flash ]

A loop of wire with current
creates a little magnet

North Pole is either
above or below the loop

Finding N. and S. Pole
of a loop of wire

Step 1 - Current travels from (-) to (+)  terminal, DRAW the direction of the current on the wire

Step 2 - Palms away, thumb in direction of current

Step 3 - Curl fingers of left hand into loop

Why Left and not right??

Step 4 - Note where four fingers tips are pointing when they enter the INSIDE of the loop

Fingers tips - NORTH POLE of the magnetic field

North Pole
 ABOVE or BELOW ??

Below

South Pole??
ABOVE or BELOW??

Above

North Pole
 ABOVE or BELOW ??

Below

North Pole
 ABOVE or BELOW ??

Above

South Pole
 ABOVE or BELOW ???

Below

If (+) and (-) terminals are reversed
the current is reversed.

Magnetic Poles?

Poles are reversed

Using magnets to
repel crocodiles

Solenoid