at the load will be greater than the system voltage. Above it, the load voltage is depressed. The Ferranti effect describes the voltage gain towards the remote end of a very lightly loaded (or open ended) transmission line. Underground cables normally have a very low characteristic impedance, resulting in an SIL that is typically in excess of the thermal limit of the cable. Practical examples The characteristic impedance of coaxial cables (coax) is commonly chosen to be for RF and microwave applications. Coax for video applications is usually for its lower loss. See also Iterative impedance, characteristic impedance is a limiting case of this References Sources External links Electricity Physical quantities Distributed element circuits Transmission lines de:Leitungstheorie#Die allgemeine L.C3.B6sung der Leitungsgleichungen