viii NOTATION. 



N f , N" number of turns of wire in the primary and secondary 



coils of a transformer. 

 n' rotor speed of an induction motor. 

 P power. Also used for leakage inductance of a trans- 

 former. 



P h hysteresis loss in a laminated iron core. 

 P 9 eddy current loss in a laminated iron core. 

 P c copper loss in a transformer. 



p number of field magnet poles, or number of polar 

 regions as in the induction motor. This letter is also 

 used for power factor, and sometimes for instantaneous 

 power. 



p' number of current paths in an armature winding. 

 <E> maximum value of harmonic alternating magnetic flux. 



Sometimes used for value of, a steady flux. 

 < instantaneous value of magnetic flux. Also used for 



angle. 



<2, q quantity of electric charge. 

 R, r resistance. Also used for radius. 

 81 magnetic reluctance. 

 s sectional area. Also used for slip of an induction 



motor. 



/ time. Also used for temperature. 

 T torque. 

 W work. 



ft> angular velocity, frequency of a harmonic alternating 



electromotive force or current in radians per second. 



X t x reactance in ohms. The letters X and x are also used 



as coordinates. 

 Y t y admittance of a circuit (= Vg z + b z or g jb). The 



letters Y and y are also used as coordinates. 

 Z, z impedance of a circuit (= Vr 1 + x 2 or r +jx). The 

 letter Z is also used for the number of conductors in 

 an armature winding, or the number of conductors in 

 a stator or rotor winding of an induction motor, or 

 the number of turns of wire in a coil. 



