ELECTRICITY AND MAGNETISM
   A = area                             B    =     magnetic field       C  =  capacitance
   d = distance                         E    =     electric field       e  =  emf
   F = force                            I    =     current              L  =  inductance
    l = length                          n    =     number of loops of   P  =  power
                                                   wire per unit length
   Q =        charge                    q    =     point charge         R = resistance
   r =        distance                  t    =     time                 U = potential
   V =        electric potential        v    =     velocity or speed    r = resistivity
   fm =       magnetic flux             k =        dielectric constant
           1 q1 q2                          dQ                                    dl
F=                                     I=                                 e=-L
      4p Î0 r 2                              dt                                   dt
      F                                        1          1                     1 2
E=                                     U C = QV = CV 2                    UL =    LI
       q                                       2          2                     2
                  Q                          rl
Ñò E × dA = Î      0
                                       R=
                                              A
                                       V = IR
          dV
E =-                                   RS = å Ri
          dr
                                                i
          1          qi
V =
      4p Î0 i ri
                 å                       1
                                            =å
                                                     1
                                        RP        i Ri
                     1 q1 q2           P = IV
U E = qV =
                   4p Î0 r
                                       FM = qv  ́ B
      Q
C=
      V                                Ñò B × d l = m I 0
      k Î0 A                           F = ò I dl  ́ B
C=
            d                          BS = m0 nI
C = å Ci
        i                              fm = ò B × dA
               1                               d fm
CP = å                                 e=-
          i   C i                                 dt
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