A two-wire dc power distribution circuit supplies six 100 W lamps located 250 ft from a dc generator. The generator voltage is 120 V and the lamp voltage should be 110 V or more. Calculate the current drawn by each lamp if its voltage is 110 V and its power is 100 W. Calculate the current in the two-wire line. Calculate the maximum resistance of the two-wire line. Calculate the resistance per unit length (in ohms/1000 ft), keeping in mind that there are two wires each 250 ft long. What size of copper wire is required? use a table of wire resistance
Hint: Sketch the circuit using wire resistance as Rw. Assume the lamp voltage is 110 V, calculate the current to deliver 100 W to each lamp. Then calculate the line current Iline. Ohm's law and KVL will give equations that can be solved for Rw.