Resistor capacitance which affect the relation between voltage and current in alternating current circuits. The ohm (symbol: Ω) is the SI unit of electrical resistance, named after Georg Simon Ohm. An ohm is equivalent to a volt per ampere. Since resistors are specified and manufactured over a very large range of values, the derived units of milliohm (1 mΩ = 10 Ω), kilohm (1 kΩ = 10 Ω), and megohm (1 MΩ = 10 Ω) are also in common usage. The total resistance of resistors connected in series is the sum of their individual resistance values. The total resistance of resistors
Sheet resistance have the same magnitude as the sheet resistance. Typically a constant current is applied to two probes, and the potential on the other two probes is measured with a high-impedance voltmeter. A geometry factor needs to be applied according to the shape of the four-point array. Two common arrays are square and in-line. For more details see Van der Pauw method. Measurement may also be made by applying high-conductivity bus bars to opposite edges of a square (or rectangular) sample. Resistance across a square area will be measured in Ω/sq. For a rectangle an appropriate geometric factor is added. Bus