Spark image

Electrical data

Free electron concentration

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

Resistivity

Resistivity  
Constantan 47x10-8 Wm
Copper 1.69x10-8 Wm
Germanium 0.65 Wm
Nichrome 130x10-8 Wm
Silver 1.6x10-8 Wm
Silicon 2.3x10-8 Wm


Temperature coefficient of resistance of copper 43x104K-1

Relative permeability


Material Relative permeability
Mild steel 2000
Silicon-iron (4.25% Si) 9000
Supermalloy (16% Fe, 79% Ni, 5% Mo) 1 000 000


Relative permittivities (at 293 K)


Solid     Liquid     Gas  
Amber 2.8   Caster oil 4.5   Air 1.000 0536
Ebonite 2.8   Glycerol 43   Carbon dioxide 1.000 986
Glass 5-10   Ethoxyethane 4.3   Helium 1.000 07
Mica 5.7-6.7   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 80.4      
 
 
 
© Keith Gibbs 2011