Why not teach the correct way, which is from negative to positive (electron flow theory)? How can you teach people the wrong way and expect them to learn properly?
Point taken, but I did explicitly say that it is a formula for resistors in parallel. For me it's merely academically interesting to point it out. I'm in no position to criticise a professional teacher. Of course if I were a teacher, I'd do as you say and use one formula for all situations.
I know this stuff, and he should have stayed with the analogy of water. He could've easily stated potentials across resistances without the need to confuse the class with showing more resistors. Ah well.
wow this gy will confuse the crap out of you he needs to learn how to seperate circuits and simplify them so that the whole thing becomes like a circuit in series other wize on a bigger circuit with like 40 things on it in difrent combinations this gyses way will take forever you solve this one at a time seperate the circuits one at a time write it out and much esier then his way
In reality electrons are negatively charge.. so it moves toward the positive... But we assume the other to make it easier...And it doesn't affect your calculations... so even if he showed positive to negative it will not affects the maths..
Actually current can flow in both direction depending on what method. Example in conventional current will flow from positive to negative terminal and non conventional electrons will flow from negative to positive terminal.
I teach electrical science to 16 to 50 year olds, and find this video extremely confusing and far too pacy, it appears the presenters philosophy is "why simplify something when you can over complicate it"!!!!
Would you believe I have never come across this option (R1*R2)/(R1+R2) before! I reckon I could suggest both methods and let students pick the one they like, or perhaps would be familiar with. Thanks
The issue with the recurring 3 is that it gets rounded down, which - if repeated a lot - can introduce avoidable errors in the final answer.
Feel free to correct me, and thanks for taking the trouble to comment.
Acc. to Whitfield, "Electr. Craft Principles" vol 1... "product over sum... useful where R's are not whole numbers, and thus lowest common denom's not easily found."
It's also given in "Electr. Install. Calc's" vol.1, by Watkins and Kitcher.
@yerrahyouknow That formula: Rt= (R1*R2)/(R1+R2) is only good for 2 resistors in parallel. The inverse of the inverse: 1/Rt = 1/R1 + 1/R2 + 1/R3 ...etc... is for more than 2 resistors in parallel. the first formula will, of course, Not work for more than 2 resistors in a parallel circuit... Nice analogy with the water flow. I use similar ones when instructing: i.e., diodes can be compared to check valves, etc.
@yerrahyouknow That formula: Rt= (R1*R2)/(R1+R2) is only good for 2 resistors in parallel. The inverse of the inverse: 1/Rt = 1/R1 + 1/R2 + 1/R3 ...etc... is for more than 2 resistors in parallel. the first formula will, of course, Not work for more than 2 resistors in a parallel circuit... Nice analogy with the water flow. I use similar ones when instructing: i.e., diodes can be compared to check valves, etc.
@nomoreheroesanymore That only works for a pair of resistors in parallel, don't forget that. If you use the formula demonstrated in the video you'll never get the result wrong.
This is easier for meto use when calculating many parallel resistors: i need to calculate the Rtotal for R1, R2, R3. R4= (R1*R2)/(R1+R2) and then: Rt= (R3*R4)/(R3+R4)
@winwutwut In your example the Total Resistance depends in the resistors disposal on the circuit. You only demonstrated the equivalent resistance for R1 and R2 (in parallel) and the equivalent resistance for R3 and R4 (in parallel too). Now, if you have them in series you should add them. If they're in parallel you apply the rule: [ (R1//R2)//(R3//R4) ]
Acc. to Whitfield, "the international symbol for supply voltage or voltage drop has changed from V to U, the symbol for the unit of Voltage (the volt) remaining as V."
11/30? 107/11? what the! - welcome to 1963.
srkh28 9 months ago
Why not teach the correct way, which is from negative to positive (electron flow theory)? How can you teach people the wrong way and expect them to learn properly?
UniversalExpanse 11 months ago
@ xbeerxpressurex
Point taken, but I did explicitly say that it is a formula for resistors in parallel. For me it's merely academically interesting to point it out. I'm in no position to criticise a professional teacher. Of course if I were a teacher, I'd do as you say and use one formula for all situations.
Best wishes.
nomoreheroesanymore 1 year ago
this reminds me of phase 4 in ringsend intence shit
mufc99ok 1 year ago
just use the formula directly and use the calculator...bingo! what you presented is just waste of time!
maloi721 1 year ago
thanks a lot for sharing !! grazie
domyaska 1 year ago
I know this stuff, and he should have stayed with the analogy of water. He could've easily stated potentials across resistances without the need to confuse the class with showing more resistors. Ah well.
sabriath 2 years ago
simple stuff - but theres nothing wrong with punching the origional equasion it into a calculator...
1/r1+1/r2=1/rt
1/"the answer"= the total resistance of the parallel circuit.
mastergx1 2 years ago
Reminds me of college.. I should go back, LOL
curt4187 2 years ago
He knows his stuff, but I find his methods hard to absorb!
tels2006 2 years ago
@tels2006 hes good but confusing just keep it simple eh
mufc99ok 1 year ago
wow this gy will confuse the crap out of you he needs to learn how to seperate circuits and simplify them so that the whole thing becomes like a circuit in series other wize on a bigger circuit with like 40 things on it in difrent combinations this gyses way will take forever you solve this one at a time seperate the circuits one at a time write it out and much esier then his way
meyaw41 2 years ago
In reality electrons are negatively charge.. so it moves toward the positive... But we assume the other to make it easier...And it doesn't affect your calculations... so even if he showed positive to negative it will not affects the maths..
Djluv5 3 years ago
current goes from negative to positive, but math isnt affected.
gangstasal85 3 years ago 2
Definitely Not!!!
lastfurlong 3 years ago
He's no Pat Doyle...
talkshowhost16 3 years ago
This comment has received too many negative votes show
Your whole thing is wrong. the direction current is from negative to posistive. Go back to school
wuanpineda 3 years ago
He can still use the assumption of conventional flow (positive to negative) since the math works out regardless. (I think, anyway).
Joetheman416 3 years ago 6
Have you not heard of the terms 'conventional current flow', versus 'electron theory' ? ? ?
nomoreheroesanymore 3 years ago 2
Actually current can flow in both direction depending on what method. Example in conventional current will flow from positive to negative terminal and non conventional electrons will flow from negative to positive terminal.
tubeyouabc1 2 years ago
thanks for the vid!
Nadie54 3 years ago
you make more sense than my physics teacher
Daiana1818 3 years ago
The Total Resistor Formula is 1/(1/R1+1/R2) ??? is it?? for parallel? right?? and equal volts..
tookthefallforyou 4 years ago
I teach electrical science to 16 to 50 year olds, and find this video extremely confusing and far too pacy, it appears the presenters philosophy is "why simplify something when you can over complicate it"!!!!
ski291163 4 years ago
Just asking, not criticising as such, but why do you not use the formula for R's in parallel - (R1*R2)/(R1+R2) ?
Seems easier to me than remembering to invert 11/30.
And why is a recurring 3 such a big argument against decimals in favour of fractions ?
But thanks, and credit to you for putting this up.
nomoreheroesanymore 4 years ago
Would you believe I have never come across this option (R1*R2)/(R1+R2) before! I reckon I could suggest both methods and let students pick the one they like, or perhaps would be familiar with. Thanks
The issue with the recurring 3 is that it gets rounded down, which - if repeated a lot - can introduce avoidable errors in the final answer.
Feel free to correct me, and thanks for taking the trouble to comment.
yerrahyouknow 4 years ago
Acc. to Whitfield, "Electr. Craft Principles" vol 1... "product over sum... useful where R's are not whole numbers, and thus lowest common denom's not easily found."
It's also given in "Electr. Install. Calc's" vol.1, by Watkins and Kitcher.
I use these texts as an Electrical apprentice.
nomoreheroesanymore 4 years ago
@yerrahyouknow not being a dickhead but i could of told you that in year 9 haha that was very simple. But im sure it was one of the easy tasks.
sxclatino 1 year ago
@yerrahyouknow
sxclatino 1 year ago
@yerrahyouknow That formula: Rt= (R1*R2)/(R1+R2) is only good for 2 resistors in parallel. The inverse of the inverse: 1/Rt = 1/R1 + 1/R2 + 1/R3 ...etc... is for more than 2 resistors in parallel. the first formula will, of course, Not work for more than 2 resistors in a parallel circuit... Nice analogy with the water flow. I use similar ones when instructing: i.e., diodes can be compared to check valves, etc.
Jim, (23+ years electrical experience)
magnamino 1 year ago
This has been flagged as spam show
@yerrahyouknow That formula: Rt= (R1*R2)/(R1+R2) is only good for 2 resistors in parallel. The inverse of the inverse: 1/Rt = 1/R1 + 1/R2 + 1/R3 ...etc... is for more than 2 resistors in parallel. the first formula will, of course, Not work for more than 2 resistors in a parallel circuit... Nice analogy with the water flow. I use similar ones when instructing: i.e., diodes can be compared to check valves, etc.
Jim, (23+ years electrical experience)
magnamino 1 year ago
@nomoreheroesanymore That only works for a pair of resistors in parallel, don't forget that. If you use the formula demonstrated in the video you'll never get the result wrong.
xbeerxpressurex 1 year ago
@xbeerxpressurex
This is easier for meto use when calculating many parallel resistors: i need to calculate the Rtotal for R1, R2, R3. R4= (R1*R2)/(R1+R2) and then: Rt= (R3*R4)/(R3+R4)
winwutwut 1 year ago
@winwutwut In your example the Total Resistance depends in the resistors disposal on the circuit. You only demonstrated the equivalent resistance for R1 and R2 (in parallel) and the equivalent resistance for R3 and R4 (in parallel too). Now, if you have them in series you should add them. If they're in parallel you apply the rule: [ (R1//R2)//(R3//R4) ]
xbeerxpressurex 1 year ago
thanx a lot...u r a GooD Teacher :D
jesstherocka 4 years ago
hmm.. we always say U=I*R and not V=I*R O,o
Tilex1990 4 years ago
Why U?
yerrahyouknow 4 years ago
dunno.. but it's the formula symbol for Voltage.
symbol - unit - descreption
U - V - volts
I - A - amps, current
R - (Omega) - electrical resistant
P - W - watt, power
U = I*R
P = U*I
Tilex1990 4 years ago
U can be represented as E as well...:)
JoniiG 4 years ago
Acc. to Whitfield, "the international symbol for supply voltage or voltage drop has changed from V to U, the symbol for the unit of Voltage (the volt) remaining as V."
nomoreheroesanymore 4 years ago
which level is this? university?
blackcurtain84 4 years ago
Irish Secondary School - similar to final year of high school?
yerrahyouknow 4 years ago
OK, thank you! good teacher!
IbnAlDjazari 4 years ago
i find this guy confusing....
doublearon86 4 years ago
i want to learn that....!!!
silentfes 4 years ago
thnx
stella9900 4 years ago