Linked Questions

-1
votes
4answers
6k views

why would you ever put the resistor on the positive side [duplicate]

If a resistor is suppose to resist over current to the load through a cable in a series DC circuit then why would you ever place a resistor on the positive cable side instead of the negative cable ...
0
votes
3answers
162 views

How does an outlet know what wattage to put out? [duplicate]

In the UK, if that makes any difference, I was wiring a motor and then I wondered (and kinda needed to know), how does a plug socket know how much power to put out? because all the input ampages on ...
-1
votes
1answer
164 views

How multimeters measure current in this circuit? [duplicate]

simulate this circuit – Schematic created using CircuitLab In the circuit shown if current is flowing from negative side of battery to positive side how multimeter can know the existence of ...
1
vote
1answer
123 views

How does a circuit “know” the resistance? [duplicate]

This is obviously a very basic question, I'm pretty new to concepts of circuitry and so on. So, lets say you have a circuit with simply a battery, a resistor, and a multimeter measuring the current. ...
31
votes
8answers
26k views

What do I need to know about oscilloscope probes?

I've run across a Hitachi V-355 oscilloscope, and a friend who's willing to give me a deal if I want it. Unfortunately, there are no probes that come with it. I was searching for probes, only to learn ...
7
votes
7answers
3k views

Transistor - Why does amplification happen before the transistor and not after?

I know this is a noob question but I just can't find an answer for it on google search results. Well my question is basically this: How come the amplifying occurs before the transistor [red line] and ...
9
votes
4answers
39k views

Does electricity go from negative to positive or vice versa?

It's common knowledge that electrons flow from negative to positive, but I have noticed than often the direction of the current is ignored. For example, the resistor is often put AFTER the LED, or the ...
9
votes
2answers
2k views

Why doesn't it matter if a resistor is before or behind an LED wrt voltage drop?

I have read that current is always the same within a circuit, but as far as I understood voltage is not. Every electronic part I use lowers the voltage more or less, even simple wires do this. So far, ...
9
votes
4answers
5k views

Can you send data usefully over one wire, literally one wire?

It is possible to design networking systems that only use two wires: one for data and one for a common ground. Examples include 1-wire and Pin&Play. These are called single wire systems because ...
8
votes
5answers
662 views

Constant current in a circuit?

simulate this circuit – Schematic created using CircuitLab A battery pumps electrons by creating an electric field and converting electric potential energy to kinetic. Near the positive ...
4
votes
3answers
1k views

Parallel and Series Circuits Question (Electron Flow)

So this is a pretty basic question, I understand the aspects of parallel and series circuits but don't understand why? For instance: How can the Battery be "drained" faster when say 3 LEDS are ...
7
votes
3answers
1k views

Arduino Question regarding the resistor

I was instructed to set up a resistor on the negative side of the LED and pulling it to ground. I'm confused why we are implementing a resistor on the backside (negative end) of the LED. I always ...
7
votes
2answers
408 views

How does current flow in this path when all points are at the same potential?

If the potentials at points A,B,C .. etc are at the same potential as the battery wrt the ground, how does current flow then? I'm lacking something fundamentally so it would be helpful if someone ...
1
vote
4answers
686 views

Very Basic Electronics Question regarding current flow

This would be considered a basic electronics question that I should know (I've been all over the place with questions tonight and I apologize). But anyways using this circuit (It's a TTL SR latch) ...
4
votes
1answer
428 views

Impedance of waveguides shorter than 1/10 of wavelength

I read already several times that it is a common rule of thumb, that matching the impedance of a waveguide to the external network impedance is only necessary for waveguides longer than 1/10 of the ...

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