Surhone Lambert M

Resistivity Surhone Lambert M

Publisher Marketing: Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Electrical resistivity (also known as specific electrical resistance or volume resistivity) is a measure of how strongly a material opposes the flow of electric current. A low resistivity indicates a material that readily allows the movement of electrical charge. The SI unit of electrical resistivity is the ohm metre ( m). The reason resistivity has the units of ohm-metres rather than the more intuitive ohm per metre ( /m) can perhaps best be seen by transposing the definition to make resistance the subject. The resistance of a given sample will increase with the length, but decrease with the cross sectional area. If one uses the common hydraulic analogy, pushing 5 gallons per minute through a garden hose would meet with some resistance. 5 gpm through a 4" diameter pipe would be relatively easy, requiring less pressure. Cross sectional area reduces resistance. Similarly, a 12 ft garden hose will fill a 5 gallon bucket in a certain amount of time. Filling the same bucket from the same spigot but with 500 feet of hose will fill the bucket in a significantly longer time. Length increases resistance.