20.  NOMENCLATURE 

93.  The  following  nomenclature  and  symbols  of  the  quantities 
most  frequently  used  in  electrical  engineering  appears  most 
satisfactory,  and  is  therefore  recommended.  It  is  in  agreement 
with  the  Standardization  Rules  of  the  A.  I.  E.  E.,  but  as  far  as 
possible  standard  letters  have  been  used,  and  script  letters  avoided 
as  impracticable  or  at  least  inconvenient  in  writing  and  still 
more  in  typewriting.  Therefore  F  has  been  chosen  for  m.m.f., 
and  dielectric  field  intensity  changed  to  K.  Also,  a  few  symbols 
not  contained  in  the  Standardization  Rules  had  to  be  added. 


NOMENCLATURE 

TABLE  OP  SYMBOLS 


119 


Symbol 

Name 

Unit 

Character 

E,  e. 

Voltage 

Volt 

Electrical 

I,  i.  . 

Potential  difference 
Electromotive  force 
Current 

Ampere 

Electrical 

R,r 

Resistance 

Ohm 

Electrical 

x 

Reactance 

Ohm 

Electrical 

Z,z... 

Impedance 

Ohm 

Electrical 

a 

Conductance 

Mho 

Electrical 

b 

Susceptance 

Mho 

Electrical 

Y,y  
p  

Admittance 
Resistivity 

Mho 
Ohm-centimeter 

Electrical 
Electrical 

7  
$  

Conductivity 
Magnetic  flux 

Mho-centimeter 
Line;  kiloline;  megaline 

Electrical 
Magnetic 

£....... 
H 

Magnetic  density 
Magnetic    field    inten- 

Lines   per    cm.2;    kilo- 
lines  per  cm.2 
Lines  per  cm  2 

Magnetic 
Magnetic 

/*        •  • 

sity 
Permeability  (magnetic 

Magnetic 

/  

conductivity) 
Magnetic  gradient 

Ampere-turns  per  centi- 

Electrical 

F 

Magnetizing  force 
Magnetomotive  force 

meter. 
Ampere-turns 

Electrical 

R  

Reluctance     (magnetic 

Electrical 

L  
M  

S      ..     . 

resistance) 
Inductance 
Mutual  inductance 
Self-inductance 

Henry;  milhenry 
Henry;  milhenry 
Henry;  milhenry 

Magnetic 
Magnetic 
Magnetic 

*,Q  

D  
K  

Leakage  inductance 
Dielectric  flux 
Electric      quantity     or 
charge 
Dielectric  density 

Dielectric    field   inten- 

Lines of  dielectric  force 
Coulombs 

Dielectric  lines  per  cm.2 
Coulombs  per  cm.2 

Dielectric 

Dielectric 
Dielectric 

k 

sity 
Permittivity 

Dielectric 

Specific  capacity 

120     ELEMENTS  OF  ELECTRICAL  ENGINEERING 

TABLE  OF  SYMBOLS.     Continued 


Symbol 

Name 

Unit 

Character 

9  

Dielectric  gradient 

Volts  per  centimeter 

Electrical 

Voltage  gradient 

Electrifying  force 

C  

Capacity 

Farad;  microfarad 

Dielectric 

P,P  

Power,  effect 

Watt;  kilowatt 

General 

W,w.... 

Energy,  work 

Joule;  kilo  joule 

General 

T,#  

Temperature 

Degrees  Centigrade 

General 

t  

Time 

Seconds 

General 

$,$,0... 

Time  angle 

Degrees  or  radians 

General 

<*,T  

Space  angle 

Degrees  or  radians 

General 

/  

Frequency 

Cycles  per  second 

General 

PART  II 

SPECIAL  APPARATUS