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