I know there are thousands of questions about electricity, but ...
1 - Do amperes matter as far as the power supply is concerned, as long as it is equal or higher than the device pulling the electricity?
Ex - I have a device that is 24V and 3A. Can I have a power supply that is 24V and 30A? Will the device just draw 3A?
2 - Using the waterfall/waterhose analogy, why don't higher Volts always equate to higher Amps? If Volts are the driving force (or potential difference) between 2 points, wouldn't a higher force mean a higher amount of electricity is being pushed across that point? Using the water hose analogy, if I have a pipe of a certain diameter (resistance), and I turn the pressure up (volts), then more water will come out of the hose at a faster rate(amperes). I'm assuming there's a difference between electricity and the water hose analogy when it comes to this.
3 - Does resistance just affect voltage, or can it affect amperes?
4 - Does all of the electricity you use in your home (that you pay at the meter) get consumed within the devices and circuitry within your home, or does extra go back?
Answers & Comments
Verified answer
1) In general, that is correct. Any current rating for a supply is giving a maximum for the load. Drawing less should work fine.
2) In a simple resistor circuit, if you leave everything else alone then higher voltage does mean higher current. It might not be true in some specific situation though. You'd need to give an example where this happens. If you put a lightbulb into a higher voltage supply, it will draw more current (perhaps more than it can take and it will burn out).
3) Resistance, voltage, and current are all related. Usually current isn't a knob you tweak. Usually current results from particular voltage and particular resistance. I'm not sure what you mean by "resistance affects voltage". There are different ways to interpret that (are you talking about a voltage supply or the voltage drop across a component?)
4) You'd normally think of it that devices use a particular amount of power and that power is monitored at the meter. It's not that power (or electricity) is delivered to the home and then unused is returned.
1 - Amperes measures the amount of electrons that move through a resistance. Voltage is the applied force. You should take into account both voltage and amperes and the resistance when dealing with a circuit as all three are required. More amperes in a series circuit may not be a good thing. More voltage in a parallel circuit may not be a good thing.
2 - Actually, increasing voltage would in return increase the RATE of amperes, thus requiring less amperes to achieve the desired outcome. For example, heaters will heat faster when supplied with 240, Less amperes are required to achieve the SAME heat, because they move faster.
3 - Resistance effects both. It is in fact the quintessential requirement for any circuit. Neither voltage nor amperes would be unless there was resistance.
4 - Unlike water, which flows down the drain when your done washing, A/C is alternating back and fourth 60 times a second. Whatever goes back out on the ground to the transformer is called the imbalanced load, and in theory is very small on residential homes. Suffice to say imbalance loads are not good and cost the power company money. On commercial sites, the power company will charge extra for high imbalanced loads. This is technically called the reactive loads.
1 yes: if the device is 24V / 3A it will only pull 3 A and only part of the time. assume a microwave oven: it only pulls power when cooking. If it is cooking 3 minutes at 50% using a 12 sec interval it pulls lots of current for 12 sec then very little for 12s then lots... when it is only showing the clock it uses milli-amps.
2The water hose analogy is correct. Up the pressure and the flow increases.>>up the voltage and the current increases. I=E/R : R is constant E ^ so I ^.
3 E, I & R effect each other E=I*R, R=E/I, I= E/R.
The meter measures what's consumed. There is no extra.
All of the power is consumed as heat, light and motion.( work)