Spark image

Electrical data

Free electron concentration

  m-3
Copper 8.5x1028
Lithium 4.7x1028
Sodium 2.7x1028
Silver 5.9x1028


Resistivity

Resistivity Ωm
Aluminium 2.65x10-8
Constantan 47x10-8
Copper 1.69x10-8
Germanium 0.65
Nichrome 130x10-8
Silver 1.6x10-8
Silicon 2.3x103


Temperature coefficient of resistance

Copper 43x10-4 K-1

Relative permeability

Mild steel 2000
Silicon-iron (4.5% Si) 9000
Supermalloy (Fe 16%, Ni 79%, Mo 5%) 1.0x106
Iron (pure) 200 000
Air 130x10-8


Relative permittivity (at 293 K)

Solid     Liquid     Gas  
Amber 2.8   Castor oil 4.5   Air 1.000 000
Ebonite 2.8   Glycerol 43   Carbon dioxide 1.000 986
Glass 5-10   Ethoxyethane 4.3   Helium 1.000 07
Mica 5.6-6.7   Nitrobenzene 35.7   Hydrogen 1.000 27
PVC 4.5   Paraffin 2.2   Nitrogen 1.000 580
Polystyrene 2.55   Propanone 21.3   Oxygen 1.000 53
Teflon 2.1   Turpentine 2.23   Water vapour (393 K) 1.000 60
Wax 2-2.3   Water (de-ionised) 80.4      

 
 
 
© Keith Gibbs 2013