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The preparation of salt solutions often takes place in unsealed beakers. In this case the conductivity of purified water often is 10 to 20 times higher. A discussion can be found below. Typical drinking water is in the range of 200–800 μS/cm, while sea water is about 50 mS/cm [3] (or 0.05 S/cm).
The siemens (symbol: S) is the unit of electric conductance, electric susceptance, and electric admittance in the International System of Units (SI). Conductance, susceptance, and admittance are the reciprocals of resistance, reactance, and impedance respectively; hence one siemens is equal to the reciprocal of one ohm (Ω −1) and is also referred to as the mho.
where is the length of the conductor, measured in metres (m), A is the cross-sectional area of the conductor measured in square metres (m 2), σ is the electrical conductivity measured in siemens per meter (S·m −1), and ρ is the electrical resistivity (also called specific electrical resistance) of the material, measured in ohm-metres (Ω ...
The resistivity can be expressed using the SI unit ohm metre (Ω⋅m) — i.e. ohms multiplied by square metres (for the cross-sectional area) then divided by metres (for the length). Both resistance and resistivity describe how difficult it is to make electrical current flow through a material, but unlike resistance, resistivity is an ...
As quoted in an online version of: David R. Lide (ed), CRC Handbook of Chemistry and Physics, 84th Edition.CRC Press. Boca Raton, Florida, 2003; Section 4, Properties of the Elements and Inorganic Compounds; Physical Properties of the Rare Earth Metals
Admittance Y, measured in siemens, is defined as the inverse of impedance Z, measured in ohms: Y ≡ 1 Z {\displaystyle Y\equiv {\frac {1}{Z}}} Resistance is a measure of the opposition of a circuit to the flow of a steady current, while impedance takes into account not only the resistance but also dynamic effects (known as reactance ).
≡ 1 cm/s 2 = 10 −2 m/s 2: inch per minute per second: ipm/s ≡ 1 in/(min⋅s) = 4.2 3 × 10 −4 m/s 2: inch per second squared: ips 2: ≡ 1 in/s 2 = 2.54 × 10 −2 m/s 2: knot per second: kn/s ≡ 1 kn/s ≈ 5.1 4 × 10 −1 m/s 2: metre per second squared (SI unit) m/s 2: ≡ 1 m/s 2 = 1 m/s 2: mile per hour per second: mph/s ≡ 1 mi ...
For a typical current of 10 mA, g m ≈ 385 mS. The input impedance is the current gain ( β ) divided by the transconductance. The output (collector) conductance is determined by the Early voltage and is proportional to the collector current.