I heard that a dimmer switch/knob/potentiometer used to control the lights in a house, for example, uses the same amount of power no matter if it is just barely on, or turned up all the way, so it really doesnt matter (energy usage wise), what the switch is turned to, it will use the same amount of energy? I would think this is false, since power is volts * amps, and the voltage is pretty much constant, say "out of the wall" voltage of 110 volts, then amps is the only thing that would effect the power consumption. Amps are calculated by volts over resistance, and we already assumed volts were constant, so ressitance is therefore the only thing effecting power consumption. As you turn the dial on the potentiometer, the resistance increses or decreases, thus making the power consumption go up or down depending on a lower of higher resistance. So is my conclusion correct, or the person who I heard this from, who claims to have gotten it from an elecrtician?