Table 463 

 ELECTRICAL EQUIVALENTS 



397 



Abbreviations : int., international ; e.m.u., electromagnetic units ; e.s.u., electrostatic 

 units ; c.g.s., centimeter-gram-second units. ( Taken from Circular 60 of U. S. Bureau of 

 Standards, 191 6, Electric Units and Standards, but made consistent with Birge's values, 

 p. 77 et seq.) 



Resistance: 



1 international ohm = 

 1. 0005 1 absolute ohms 

 1. 000 1 int. ohms (France, before 191 1) 

 1. 00016 Board of Trade units (England, 



1903) 

 1.01358 B. A. units 

 1.00283 " legal ohms " of 1884 

 1.06300 Siemens units 



1 absolute ohm = 

 0.99949 int- ohms 

 1 " practical " e.m.u. 

 io 9 c.g.s. e.m.u. 

 1.11262 X io" 12 c.g.s. e.s.u. 



Current: 



1 international ampere = 

 0-99995 absolute ampere 

 i.ooo8_i int. amperes (U. S. before 191 1) 

 1. 00130 int. amperes (England, before 

 1906) 



amperes (England, 1906- 



1.00106 int. 



08) 

 1.00010 int. amperes 



10) 

 1.00032 int. 



1911) 

 1.0002 int. 



1911) 



absolute ampere = 

 1.00005 int. amperes 

 1 " practical " e.m.u. 

 0.1 c.g.s. e.m.u. 

 2.99796 X io 9 c.g.s. e.s.u. 



(England, 1909- 

 amperes (Germany, before 

 amperes (France, before 



Capacity : 



1 international farad = 

 0.99949 absolute farad 



1 absolute farad = 

 1. 0005 1 int. farads 

 1 " practical " e.m.u. 

 io" 9 c.g.s. e.m.u. 

 8.98776 X io 11 c.g.s. e.s.u. 



Inductance : 

 I international henry = 

 1.0005 1 absolute henries 



1 absolute henry = 

 0.99949 int. henry 

 1 " practical " e.m.u. 

 io 9 e.m.u. 

 1. 1 1262 X io" 12 c.g.s. e.s.u. 



Energy and Power: 

 (standard gravity = 980.665 cm/sec./sec. 

 1 international joule = 

 1. 00041 absolute joules 



1 absolute joule = 

 0.99959 int. joule 

 io 7 ergs 



0.737560 standard foot-pound 

 0.101972 standard kilogram-meter 

 0.277778 X io" 6 kilowatt-hour 



Electromotive Force : 

 1 international volt = 



1.00046 absolute volts 



1.00084 int. volts (U. S. before 191 1) 



1. 00 130 int. volts (England, before 

 1906) 



1. 00106 int. volts (England, 1006-08) 



1.00010 int. volts (England, 1909-10) 



1.00032 int. volts (Germany, before 

 1911) 



1.00032 int. volts (France, before 191 1) 

 1 absolute volt = 



0.99954 int. volt 



1 " practical " e.m.u. 



io 8 c.g.s. e.m.u. 



000333560 c.g.s. e.s.u. 



Quantity of Electricity : 

 (Same as current equivalents.) 

 1 international coulomb = 



1/3600 ampere-hour 



1/96494 faraday 



Resistivity : 



1 ohm-cm = 0.393700 ohm-inch 



= 10,000 ohm (meter, mm 2 ) 

 = 12,732.4 ohm (meter, mm) 

 = 393.70O microhm-inch 

 = 1,000,000 microhm-cm 

 = 6,015,290 ohm (mil, foot) 



1 ohm (meter, gram) = 5710.0 ohm (mile, 

 pound) 



Magnetic Quantities : 

 1 int. gilbert = 0.99995 absolute gilbert 

 I absolute gilbert = 1.00005 mt - gilberts 

 1 int. maxwell = 1.00046 absolute max- 

 wells 

 1 absolute maxwell = 0.99954 i nt - max- 

 well 

 1 gilbert = 0.7958 ampere-turn 



1 gilbert per cm = 0.7958 ampere-turn 

 per cm 

 = 2.021 ampere-turns 

 per inch 

 1 maxwell = 1 line 



= io" s volt-second 

 1 maxwell per cm 3 — 6.452 maxwells per 

 in. 2 



Smithsonian Tables 



