In electrical engineering, the power factor of an AC electrical power system is defined as the ratio of the real power flowing to the load to the apparent power in the circuit ” R/Z”.
According to the Norton theorem, to find the Norton current, first remove the load resistance RL from the network terminals AB. Short circuit the terminals AB as shown in Figure calculate the current ISc or IN through the short circuit. Now resistance of 150Ω will not show any effect in the circuit. So only resistance of 30Ω will be effective. Norton current IN = 360/30 IN = 12 A
Luminous flux measures the total radiant power reaching a surface, but without regard to surface position: the power might be concentrated on only part of the surface or spread evenly across it. Irradiance (Ee) or illuminance (Ev) is the density of incident radiant flux or luminous flux at a point on a surface and is defined as radiant flux or luminous flux per unit area, as given by E = dφ/dA where (dφ) is the radiant flux or luminous flux incident on an element dA of the surface containing the point. The unit of irradiance is Wm−2, and that of illuminance is lux
Galvanized steel conductors do not corrode, and possess high resistance. Hence such Wires are used in telecommunications circuits, earth wires, guard wire, stray wire, etc.