There are two parties to a written communication, a writer, and a reader.
That is rather an over simplified idea, I write, then the writing is turned into some form of code and sent to the reader, within that middle section all sorts can happen, raging from auto spell checking to turning into packets, to be sent, and sysop approval in some cases, using voice to text, or test to voice even more errors can exist.
I know with my tablet many times is changes what I write, so often I have to return and correct, and there will be those I miss.
I have to admit it is still a little bit of magic as far as I am concerned on how with a tuned circuit the amps can be so high, I remember doing the Q in a tuned circuit, but can't say I fully understood it. AC does not work like DC, however lucky in this case looking at DC.
In the main with a calculation we have an idea of the answer, which is just as well, I was always getting the decimal point wrong when using a slide rule.
The guy does however have some electronic components which seem at first glance not to follow what we expect. So look at 3 red LED's and a resistor connecting them to 12 volt battery, and compare with 3 green LED's and a resistor also to a 12 volt battery, I am going to assume the battery is actually 12 volt, although in real world this is unlikely to be the case. So in the red LED circuit with have a 340Ω resistor and just under 20 mA flows, but with the green we have a 280Ω resistor and still just under 20 mA flows.
Ohms law seems at first glance not to be working, this is because the LED is a current dependent device, typical voltage on red is 1.85 volt and green is 2.2 volt they don't have a fixed resistance this is dependent on the voltage.
Even a simple tungsten bulb the resistance is not constant at around 6 year old I learnt putting two 6 volt bulbs in series across my model train set tracks, that one bulb burnt out, because the mA ratings of the two bulbs were not the same. My dad explained ohm's law and I have never forgotten it.
However one to one is so much easier than with a forum, English is far harder to understand why is Happisburg pronounced Hazeborough? Unlike Granada and Canada they are not names of countries overseas, so why is it not pronounced as it sounds? No wonder they can't read and write and drive tractor!