Hi,
I applaud your efforts with this site. However, as I was browsing
through some of the "Science Snacks", I came across "Circles of
Magnatism I". At the end of the article I found a section called
"etcetera". Within this section, an effort is made to inform the reader
of a simple tech- nique, used to determine the direction of the magnetic
field induced by electric current flowing through a wire, called the
"right hand rule".
The problem is that the information is incorrect.
It states:
>To find the direction of the magnetic field made by an electrical current, use a technique >called the righthand rule.
>Place your right hand with the thumb parallel to the wire carrying the current. Point your thumb >in the direction of the electrical current in the wire.
>(Remember: The electric current flows from the plus side of the battery through the wire to the >minus side.)
>Wrap your fingers around the wire. Your fingers will now point in the direction of the magnetic >field around the wire. If there are compasses near the wire, they will point in the same >direction as your fingers.
The fact is that electric current flows from the negative side of the
battery through the wire to the minus side (always from the point of
greater negativity to lesser negativity - easily checked with a small
multimeter.). As a corollary to this, the "righthand rule" now become
the "lefthand rule"
PS: I have noted that the error has been repeated in the "Motor Effect"
article as well.
Ciao.
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