Hi, There is some basic stuff I don't understand about resistance. Legend holds it that resistance works by transforming power into heat. So why then, I a sk, would it result in decreased power usage by adding a resistor in a circ uit? In other words, let's say I have a light bulb in a 12 V circuit and th e current is 1 amp and thus the power usage is 12W. Thus the resistance is
12 Ohms, If I now add a 12 Ohms resistor to the circuit it doubles the resi stance and cuts the current and thus the power usage in half. But why? If t he lamp now uses half the power of the original circuit wouldn't the resis tor also use half the power by turning it into heat and once again the powe r usage would be 12W? Confused. Thank you,- posted
10 years ago