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

  • Thread starter Thread starter ethan12
  • Start date Start date
  • Tags Tags
    Electricity
AI Thread Summary
In the UK, the electricity supply is 230 volts at 13 amps, but appliances like hairdryers use only the current they require, which is limited by their internal resistance. The fuse rating, such as a 3 amp fuse for a hairdryer, protects the appliance by preventing excessive current flow. This concept can be compared to a water faucet, where the pressure represents voltage and the flow rate represents current, regulated by the faucet's opening. Therefore, the full capacity of the circuit does not overwhelm the appliance because it only draws the necessary amperage. Understanding this principle clarifies how devices operate within the electrical system.
ethan12
Messages
1
Reaction score
0
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.
 
Physics news on Phys.org
Welcome to PF. The amp rating of a circuit is just a capacity. The electrical device draws whatever amperage it needs.
 
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.
 
Thread 'Inducing EMF Through a Coil: Understanding Flux'

Thread 'Inducing EMF Through a Coil: Understanding Flux'

Thank you for reading my post. I can understand why a change in magnetic flux through a conducting surface would induce an emf, but how does this work when inducing an emf through a coil? How does the flux through the empty space between the wires have an effect on the electrons in the wire itself? In the image below is a coil with a magnetic field going through the space between the wires but not necessarily through the wires themselves. Thank you.
View full post »

Thread 'Reflections at the source point of a transmission line'

I was using the Smith chart to determine the input impedance of a transmission line that has a reflection from the load. One can do this if one knows the characteristic impedance Zo, the degree of mismatch of the load ZL and the length of the transmission line in wavelengths. However, my question is: Consider the input impedance of a wave which appears back at the source after reflection from the load and has traveled for some fraction of a wavelength. The impedance of this wave as it...
View full post »

Similar threads

AC Electric Neutral Current Flow
Replies
2
Views
3K
Electric Current: How Does the Battery Generate Voltage?
Replies
4
Views
1K
Electricity Question Amps & volts confusion
Replies
3
Views
2K
How Does an Electric Current Supply More Energy to Higher Wattage Appliances?
Replies
4
Views
2K
High voltage electric field does not stop electric motor
Replies
4
Views
5K
Calculating Current Draw in Electromagnetic Coil
Replies
1
Views
25K
Meaning & limitations of Volt/Current ratings
Replies
4
Views
2K
Total amperage in a service panel
Replies
41
Views
18K
Engineering How Do You Calculate Current and Power Factor in a Synchronous Induction Motor?
Replies
4
Views
4K
Solving Power Delivery Issues in a 5V Series Circuit with a 1.5V Rated Relay
Replies
12
Views
3K

Hot Threads

Recent Insights

Back
Top