How to Calculate the Resistance of Metallic Cables?
In basic engineering circuit analysis it sometimes becomes very important to know the resistance of a conductor, for example the mains cable. Let’s see how it’s calculated: Resistance of Metallic Conductors: It may be calculated using the following simple formula: R = ρ×l/a where R = Resistance in Ohms, ρ = Resistivity of the conductor material, l = Length of the conductor and a = cross sectional area of the conductor. The resistivity of the material is actually the resistance present in a meter long conductor having a cross sectional area of 1mm2 and is constant. Electrical Power: Its unit is Watt and is defined as the product of current and voltage. Hence W = IU = I2R, (by replacing U = IR). The following given problem and its solution will help us to understand the use of the above discussed two electrical parameters: click to enlargeQ: Referring to the adjoining figure, an electrical heater consuming 6 amperes of current is connected to a 220 volts supply by a copper cable having a
