How Does a Hairdryer Use Less Current Despite High Home Voltage?

[ethan12]

Hi,
The UK., electricity supply is 13 amps at 230 volts. With such a current and e.m.f., how can we run appliances which don't need that e.g., a hairdryer with a 3 amp fuse. What stops the full 13 amps overwhelming the appliance? My question is not well put but I'm sure you know what I'm getting at. I'm a parent trying to help my son and I would like to give him the right answer even if the answer might take some thinking about. It's not for his homework just for our understanding.
Thank you for reading this.
Regards,
Ethan12.

 

[russ_watters]

Welcome to PF. The amp rating of a circuit is just a capacity. The electrical device draws whatever amperage it needs.

 

[Lsos]

For a given amount of voltage, the current goes down as the resistance goes up, and the hair dryer has a certain amount of resistance in it.

You can think of similar situation with a water faucet. The pressure of the water is the voltage, and you can regulate the current by opening or closing the faucet.

I don't know much about electricity and I'm kind of talking out of my *** and/or oversimplifying it, so someone correct me if they can.