physics / fields-essential.mdon commit Merge branch 'master' of ssh://charles/tank/andrew/school/notes (06ac421)
   1# Fields - essential notes
   2
   3- Magnetic field always acts N -> S
   4- Current always flows +ve to -ve
   5- Motors- AC (slip ring) or DC (split ring)
   6- Dot means out of page, cross means into page
   7- ${E_1 \over E_2}={r_1 \over r_2}^2$
   8- charge produced by gravity = $GM$