Not professionally of course. I just want to get an idea of how much I know compared to some of the professionals on the forum and where I can expand my knowledge.
The things I know (not much):
A circuit will usually only draw as much current as it needs.
Ohm's law.
Capacitors smooth voltage signals.
Diodes make sure voltage signals are going in the right direction but also have a voltage drop and can be used for power regulation.
Resistors manipulate Ohm's law to only allow a certain level of current through a system. However small resistors regulating large current is a bad idea.
The electrons move in the opposite direction as the current flow.
Current is how fast the electrons are moving and voltage is the power they have behind them.
Noise is a thing.
Basic logic (OR, AND, XOR, NOT).
AC and DC.
What I want to learn:
Transistors and MOSFETs.
Why do LEDs burn themselves out?
Complex logic.
Resonance.
Electrical math.
Inductors.
More complex uses for diodes, capacitors, and resistors.
I can't suggest any resources... It's too long since I was in school..
But I'll hit you with a couple of simple answers...
They don't. Like most electronics they pretty much "last forever" as long as they are operated within spec. In general, solid state electronics tend to fail "randomly". i.e. They are just as likely to fail in the 1st week as the 100th week. I work in electronics and I've seen some dead-on-arrival LEDs and I've seen some that were wired backwards internally but I don't remember ever seeing one fail in the field.
LEDs are diodes and like all diodes they are non-linear. Their resistance drops as voltage increases above the forward operating voltage if the voltage goes-up a little the current (and power) goes-up a lot and it will burn-out if you don't limit the current. So, we use a current limiting resistor (or a special constant-current supply for higher-power LEDs) and the voltage "magically falls into place".
As you may know, diodes are commonly used as rectifiers in power supplies (it's the main component for converting AC to DC). In this case, the load limits the current.
BTW - Ohm's Law is a law of nature (with man-made units-of-measure) and it's always true. But we can't easily apply Ohm's Law directly to LEDs because we usually don't know the resistance.
Simplified: Inductors "resist changes in current". If you have current flowing through an inductor and you disconnect it, you get a very-high voltage for a short period of time as the magnetic field collapses and it "tries" to keep the current flowing through an infinite resistance. Since the inductor is now a "generator" the voltage is reversed. (i.e. Current flows from negative to positive inside a battery.)
In series an inductor is a low-pass filter (as it "resists" changes in current direction). In parallel it can be part of a high-pass filter.
Capacitors "resist changes in voltage". In series they are high-pass filters (DC is zero-Hz and they block DC current flow) and in parallel they can be part of a low-pass filter.
If you take an electronic engineering, inductors & capacitors are defined with calculus....
I has multiple meanings but it's really just a common connection and a reference. Sometimes circuit ground is connected to earth-ground and sometimes not.
In your car the negative battery terminal is connected to the body/chassis and that's considered ground, but since you have rubber tires there is obviously no connection to earth ground. You can measure 12V relative to the car body but you won't measure any voltage between earth ground and the car battery. (I think some old cars were positive-ground.)
If you power your Arduino from a battery, the Arduino ground isn't earth-ground unless you make a separate connection. If you power it from your laptop's USB port it's (probably) not earth grounded, but a desktop's ground usually is connected to earth ground. It's also possible that another USB port on the computer is connected to something that's earth grounded, and then there will be an earth-connection to your Arduino too.
The ground on the power outlets in your house is earth-ground.
It's a fuse that automatically resets itself.
It's not. Except the AC power in your house is 120v or 240V, and anything above 50V is considered dangerous (by the regulatory agencies). But you should know that AC is normally measured in RMS (a kind of average) and 120VAC has a peak of about 170V, so 50VAC might be considered slightly more dangerous than 50VDC.
....The Edison (DC) vs Tesla (AC) feud was mostly propaganda. AC is more dangerous simply because the voltages are higher... Higher voltages are used with AC because it's easy to convert from high-voltage/low-current to low-voltage/high-current with transformers. And high voltage (and lower current) power transmission is a lot more efficient because wire has resistance and the voltage loss is proportional to current (Ohm's Law). As an added bonus, the voltage loss is a smaller percentage.... If you loose 10V out of 100V, that's bad but if you loose 10V out of 10,000, that's nothing.
Of course you could run high-voltage DC over long distances too but it's not easy to step-down. In the days of Edison & Tesla they would have used a dynamotor (a motor and generator) and it's just a lot easier, cheaper, and more reliable with AC transformers.
Never been locked. But the last close call a few years ago, the screwdriver I was holding missed my eye by a centimeter and made a bloody gash in my face. Never become complacent.
IMHO "ground" is a misnomer for all but geophysical circuits.
Long ago scientists recognized that an electrical current could flow through the earths "crust". Folks erroneously assumed the voltage in the ground where ever they were standing was the same everywhere. The started to think of it as an absolute. It is not.
Terminology being more social that scientific used the term "ground" for any "common" or "reference" voltage.
Capacitors:
You might look at the characteristics and limitation of differernt types of capacitors. Since we don't have the ability to make a "perfect" capacitor we find that different type of capacitors excel in certain applications where others do not.
Quite a big list. You can read 'Digital logic design' by Morris Mano and 'Operational Amplifiers and Linear Integrated Circuits' by Coughlin and Driscoll.
Here is a good block regarding the basics of transistors:Introduction to Transistor - The Engineering Projects
A circuit will only draw as much current as it needs to kill a LED
Perhaps you might save some LEDs, if you remove the first post off your "known things" list.
Or, as you know "Ohm's Law", remember that not everything has a constant resistance.