When I attach a battery to a breadboard with a resistor, is the resistor considered a 'load' that consumes current?
If that's all that's connected across your battery terminals then "yes"
The resistor is the load across the battery and hence current flows. The resistor "consumes" power (not current) and that power is the product of voltage across the resistor times the current flowing. The current flow is determined from the equation I = V/R.
We don't say consumed because the same current flows all the way round the circuit,
like the blood round the circulatory system... The energy or power needed to push the current
through the resistor comes from the battery and ends up as heat in the resistor. By the same
analogy that's like the oxygen in the bloodstream (not the best analogy I'd admit).
Sounds like you need to meet Mr. Ohm and ask him about his LAW.
If that's all that's connected across your battery terminals then "yes"
Most likely this is not what he had in mind.
When I attach a battery to a breadboard with a resistor, is the resistor considered a 'load' that consumes current?
He is mentioning a breadboard so most likely there are other components on the breadboard that comprise the rest of the circuit.
Neither the resistor nor the rest of the circuit is 'consuming' current (as explained previously). The resistor is 'limiting' the current in the circuit. In the process there is a voltage drop across the resistor (as defined by Mr. Ohm) and the voltage available to the rest of the circuit is lower than it was before the introduction of the resistor.
Don
It's worth noting that in aggregate, a certain current flows through the circuit, from one pole of the current source to the other (it is said to flow from positive to negative in "conventional" flow and the other way in "electron" flow, but it does not matter). Any point of the circuit that introduces a voltage drop will produce heating equivalent to the voltage drop * the amount of current flowing through that part of the circuit. If that is what you mean by a resistor consuming current, then yes, that will happen. For the whole circuit, it will be the entire voltage drop which is rail to rail times the current of the whole circuit, minus other radiated energy that might be produced such as radio, visible light, etc..
MarkT:
We don't say consumed because the same current flows all the way round the circuit, like the blood round the circulatory system... The energy or power needed to push the current through the resistor comes from the battery and ends up as heat in the resistor. By the same analogy that's like the oxygen in the bloodstream (not the best analogy I'd admit).
The term "consume" is a bit odd. The better term would be "permit".
When you turn your tap on, it does not "consume" water - it permits water to flow out, and a resistor allows current to flow. A tap barely turned on has a high resistance and permits only a small flow, as it is turned on more, a lower resistance permits a heavier flow.
That water may be "consumed" by something else and do some useful work (such as quenching your thirst).
The term "consume" is a bit odd. The better term would be "permit".
It seems to me that in accordance with the name that was chosen for these devices the better term would be "resist" and the description should be be given from the opposite viewpoint (the pessimistic one??).
Don
Resistors "restrict" current, "dissipate" power and "consume" energy.
floresta:
It seems to me that in accordance with the name that was chosen for these devices the better term would be "resist" and the description should be be given from the opposite viewpoint (the pessimistic one??).
What? Just because they were not named "permitters"? Or "encouragers"?
I suppose the name is to make a distinction with "conductors", but then "permitters" would simply be a distinction with "insulators".
Of course they consume current
Just as you consume food , thy turn it into heat.
Perhaps energy would be a better word
I thik th op needs to research the meanings of energy power and current a bit
And probably ohms law.
Not a daft question though from someone who sounds like a beginner
AARRGGHH
cybefox:
When I attach a battery to a breadboard with a resistor, is the resistor considered a 'load' that consumes current?
the energy flowing through the resistors will deliver some of that to the resistor in the form of heat. so, in answer to your question, yes. you have to account for the energy.
we very generally lump resistors into two categories, signal and power. used with an LED, they limit the the power. when used with a motor, the current flowing through can be watts, and the resistors can deliver quite a bit of heat.
any time you are in a battery operated device, every part needs to be engineered to be most efficient.
As was noted, it would be more proper to say they consume power.
an interesting example would be to have 1 volt LED's and 12 volt power supply.
use one resistor and say, 10 LED's calculate the voltage drop needed by the resistor
under this example. 10 LEDs at 1 volt would mean the LED's in series would drop the voltage by 10 volts.
so, the resistor only has to drop from 12 to 10, or 2 volts. in addition, if each LED were 20mA, the series wiring would require the resistor to pass 2 volts and 20mA, the resistor would draw 40mW, so a 1/4 watt resistor would be fine.
if, you used 10 LED's at 1 volt and 10 resistors, one per LED. then the resistor would have to drop from 12 to 1 and still only need to pass 20mA. each resistor would need to drop 224mW and you would be best with a 1/2 watt resistor.
but, since you have 10 of these, and each consumed 224mW of power, the total resistors would consume 2.24 watts of power.
As you can see by the various answers, the wording of the question is very important.
Boardburner2:
Of course they consume current.
If that were true, there would be fewer amps out than there in, surely?
dave-in-nj:
the energy flowing
Energy doesn't flow.
JimboZA:
Energy doesn't flow.
In physics, energy is a property of objects, transferable among them via fundamental interactions, which can be converted into different forms but not created or destroyed.
I pretty much use that as what happens and transfer from one to another and then back to the original through a circuit.
probably not worth any discussion as it is a trivial point. I will try to be more proper in the future. but for now. I plan to watch coffee flow into my mug and then into my mug and then watch water flow from the shower head.
And in so doing the flow of coffee will be the flow of energy from the coffee to you and the cold shower flow will energise you, so yep ok! energy flows.....
JimboZA:
If that were true, there would be fewer amps out than there in, surely?Energy doesn't flow.
Erm yes i was in the process of composing and editing that when battery failed
I think this thread has consumed enough time.