Over and over I'm getting into the same trouble, so I'd like toask for some help.
- I need to solve some basic electrodynamics problem, involvingmagnetic fields, moving charges or currents.
- But I forgot all this rules about \"where the magnetic fieldshould go if the current flows up\". I vaguely remember that itabout hands or fingers or books or guns, and magnetic field shouldgo somewhere along something, while current should flow alongsomething else... But it doesn't help, because I don't remember thedetails.
- I do find some very nice rule and use it. And I think \"that oneI will never forget\".
- ...time passes...
- Go to step 1.
The problem is that you have to remember one choice from adichotomy: \"this way or that way\". And all the mnemonics I knowhave the same problem -- I got to remember \"left hand or righthand\", \"this finger or that finger\", \"inside the book or outside ofthe book\".
Maybe someone knows some mnemonics, that do not have suchproblem?
