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”.
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.
The resistance R3 & R4 are connected in series = (30 + 70) = 100Ω Now three resistor i.e 100Ω, 100Ω & 50Ω is connected in parallel 1/Rp = 1/100 + 1/100 + 1/50 Rp = 100/4 = 25 Ω Resistance 50Ω and 25Ω are connected in series. Rtotal = (50 + 25)Ω Rtotal = 75Ω