How Does an Electric Current Supply More Energy to Higher Wattage Appliances?

  • Thread starter esmeralda4
  • Start date
  • Tags
    Watt
In summary, the conversation discusses the relationship between electric current, resistance, and power in different wattage appliances. The expert explains that the lower resistance device draws more current and produces more heat energy, resulting in a brighter light. The expert also compares the process to that of an electric stove's heating element. Lastly, the conversation encourages asking questions and emphasizes that there is no such thing as a stupid question.
  • #1
esmeralda4
52
0
Ok, I'm preparing to get shot down here because maybe this is a really dumb question but here we go...

How does an electric current know to supply more energy (joules per second) to higher wattage appliances?

For example:

At home I can plug a 10W, 50W, 60W or 100W light bulb into a socket and they all work and emit different brightnesses. Why?

What is it about the 100W light bulb that makes it draw more power? It is the resistance? If so does it have more or less than a 60W? Iif it has less R then surely it wouldn't get so hot and therefore so bright and if it had more R then, well, I can't understand why that would make it bright either.

Have I just asked the most stupid question ever on Physics Forum? If anyone can help me clear this up that would be great.

Thanks.
 
Physics news on Phys.org
  • #2
V = IR and Power = VI . Does it answer your question ?

P.S And this is the worst explanation ever :P
 
Last edited:
  • #3
esmeralda4 said:
At home I can plug a 10W, 50W, 60W or 100W light bulb into a socket and they all work and emit different brightnesses. Why?
You are right in saying that the lower resistance device draws more current. With the house voltage being the same in each case, then the lowest resistance bulb is delivered the most power, i.e., the most heat energy, so it's able to produce the most light energy.
What is it about the 100W light bulb that makes it draw more power? It is the resistance? If so does it have more or less than a 60W? Iif it has less R then surely it wouldn't get so hot and therefore so bright and if it had more R then, well, I can't understand why that would make it bright either.
If you lower the resistance then it draws more current. Power = voltage x current

The reason different metal resistances glow differently is almost entirely due to the temperature of their surface, the hotter each tiny glowing area on the surface, the whiter (or bluer) it glows. To cause a small flashlight bulb's filament to glow about as white as does the filament in your large 100W bulb, despite the greatly reduced power in the smaller bulb, the filament is wound smaller and is much thinner and shorter in order to concentrate the heat energy in a small volume of filament metal and raise the local surface temperature to nearly that of the local surface temperature of the larger bulb's much larger filament. The rarified gases in the bulb are designed to reduce the rate at which heat escapes from the bulb, meaning less electrical energy is needed to maintain the high temperature of the glowing filament.

Compare the incandescent light bulb with the heating element on your electric stove. Your stove element is a much lower resistance so draws much greater current and generates a lot more heat energy. But the stove element has much greater volume (it's very thick and also much longer) than the filament in any light globe so the heat energy distributed over the element's much greater surface area fails to raise the local surface temperature much above a dull red glow. The heat is not concentrated in a small space and so fails to raise the temperature nearly as much as happens in a light bulb, before the element's heat escapes to warm the metal of the saucepan resting on it.

I hope that helps you to make the resistance ⇒ power ⇒ heat ⇒ temperature connection.
i0om5.gif


:smile:
 
  • #4
esmeralda4 said:
Have I just asked the most stupid question ever on Physics Forum? If anyone can help me clear this up that would be great.

It is better to remain silent and be thought a fool than to speak out and remove all doubt. Jokes apart, stupid is one who had a question but made no effort to get an answer. Feel free to ask more questions.
 
  • #5
:smile:
esmeralda4 said:
Have I just asked the most stupid question ever .
remember: "the only stupid question is the one you never asked"
 
Last edited:

1. How does an electric current supply more energy to higher wattage appliances?

Electric current works by transferring energy from an electrical source, such as a power plant, through a circuit to power various devices. The amount of energy that is transferred depends on the voltage and current of the circuit. Higher wattage appliances require more energy because they have a larger power rating, which means they use more electricity to operate. This is why they need a higher electric current to supply the necessary energy.

2. What is the difference between voltage and current in relation to supplying energy to appliances?

Voltage and current are two important factors in understanding how electric current supplies energy to appliances. Voltage is the force that determines how much energy is transferred in a circuit, while current is the rate at which the energy is transferred. It is similar to the concept of water pressure (voltage) and flow rate (current) in a pipe. Higher voltage means more energy is available to be transferred, while higher current means the energy is transferred at a faster rate.

3. Can higher wattage appliances be powered with lower voltage and current?

In theory, it is possible to power a higher wattage appliance with lower voltage and current. However, the appliance will not be able to function properly as it requires a certain amount of energy to operate. Lower voltage and current may lead to slower and less efficient operation, or the appliance may not work at all. It is important to use the correct voltage and current for each appliance to ensure proper functioning and to avoid potential safety hazards.

4. How does the type of current, AC or DC, affect the energy supply to appliances?

The type of current, whether it is AC (alternating current) or DC (direct current), does not affect the amount of energy supplied to appliances. Both AC and DC can supply the necessary energy to power appliances. However, the type of current may affect the efficiency and performance of certain appliances. For example, some appliances are designed for AC while others require DC, and using the wrong type of current may lead to malfunction or damage.

5. How can I calculate the amount of energy supplied to an appliance?

The amount of energy supplied to an appliance can be calculated using the formula: Power (wattage) = Voltage x Current. This formula is known as Ohm's Law and is used to determine the power (in watts) consumed by an appliance. By knowing the voltage and current of the circuit, you can determine the amount of energy that is being supplied to the appliance. This information can be useful for understanding the energy usage and efficiency of your appliances.

Similar threads

I Why does resistance reduce current in whole circuit?
    • Classical Physics
2
Replies
38
Views
2K
Astounding new discovery on Electrical Heat
    • Electromagnetism
Replies
7
Views
3K
How conductors/resistors affect electric fields?
    • Electromagnetism
Replies
1
Views
2K
Load resistance and current “draw”
    • Electrical Engineering
Replies
8
Views
4K
Why does an electron shell further away from nucleus has higher energy?
    • Electromagnetism
Replies
13
Views
4K
Underanding voltage and electron's energy loss
    • Electromagnetism
Replies
7
Views
2K
Current, voltage : brightness of bulb in parallel or series
    • Introductory Physics Homework Help
Replies
2
Views
3K
How does electrical energy perform work?
    • Electromagnetism
Replies
4
Views
3K
Electric load: Some explanation?
    • Electrical Engineering
Replies
7
Views
1K
Troubleshooting Car Electrical Issues: Understanding Grounding and Wattage
    • Electrical Engineering
Replies
2
Views
1K

Hot Threads

Recent Insights

Back
Top