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tranceical

- 23

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Sorry in advance if my questions are stupid and the answers are obvious.

I can see from P=VI why a high power appliance requires more current to function. However looking at ohms law and I=V/R it’s telling me that greater resistance will lead to less current. I've always figured that high power appliance or the load on something like a motor would have an inherently higher resistance/impedance, which is why it requires more power. In my head if a motor is working harder or has more physical resistance on its output shaft then it requires more power to function.

From trying to find an answer I read this on Wikipedia:

“Mains power outlets provide an easy example: they supply power at constant voltage, with electrical appliances connected to the power circuit collectively making up the load. When a high-power appliance switches on, it dramatically reduces the load impedance.”

Why would turning on a high power appliance reduce load impedance? If something needs more power, more work to be done then surely higher impedance exists.

Please help me marry up the relationship between the current a load draws with its inherent resistance and ohms law.

Many thanks