The esu or Gaussian system

 

Quantity

Symbol

Units in MKS  system

Units in CGS or Gaussian system

Distance

x

meter

102 cm

Force

F

Newton

105 dynes

Work, energy

W

Joule

107 ergs

Charge

q

Coulomb

2.998 x l09 esu

Current

I

ampere

2.998 x esu/sec

Electric Potential

f

volt

(1/299.8) statvolts

Electric field

E

volts/meter

(1/29980) statvolts/cm

Resistance

R

ohm

1.139 x10-12 sec/cm

Magnetic field

B

Tesla

104 gauss

Magnetic flux

F

Weber

108 gauss-cm2

Auxiliary field

H

amperes/meter

4p X 10-3 oersted

 

 

Example

 

MKS

CGS

 

 

F = [1/4πe0] × q1q2/r2

 

F = q1q2/r2

 

 

 

If two charges of 1 C are separated by 1 mm then the force in CGS units is

 

F = 1 C × 1 C × [2.998 x l09 esu/C]2 / [0.1 cm]2 = 8.988 x l020 dyne

 

 

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