For dimming bulbs, Xiao Ming thinks that when the lamp is dark, it saves more power than when it is on, but Xiao Lin thinks that when the lamp is dark, the power of sliding rheostat increases, so it doesn't save power. Q: who is right? Briefly describe your reasons (Baidu has many different answers, Dashen must do it by himself!)

For dimming bulbs, Xiao Ming thinks that when the lamp is dark, it saves more power than when it is on, but Xiao Lin thinks that when the lamp is dark, the power of sliding rheostat increases, so it doesn't save power. Q: who is right? Briefly describe your reasons (Baidu has many different answers, Dashen must do it by himself!)

Kobayashi's opinion is not unreasonable. According to the series knowledge of the circuit, the current in the circuit is the same. When the resistance of the rheostat increases, the current in the circuit decreases. According to P = I * I * r, the power consumed by the electric lamp decreases, but the power consumed by the rheostat is uncertain, because there are two variables, I and R, which change