Well you probably have the correct answer, but that doesn't mean you aren't a failure
Sorry, just kidding, couldn't help myself, left handed you know.
Lefty
PS: and yea, if this thread had started in a bar the fight would have long been broken up and we all would be recovering with hangovers and wondering WTF.
Because resistors in parallel decrease total resistance. Is that a trick question somehow? Did I fail? =)
For some reason, I have failed to see your point.
Not even when Europe's finest universities taught that the Sun revolved around Earth, and that comets were harbingers of God's wrath? **broken link removed** **broken link removed**
Here is another proof that Ohm's Law doesnt work for a resistance taken
to a power:
V=R*I
and for example with a 2 ohm resistor:
2v=2 ohms * 1 ampere
and changed around:
2 ohms=2v/1A
and the units are:
ohms=volts/amperes
Now if R is not a constant but allowed to vary as R^2 we have:
2v=(2 ohms)^2 * 1 amp
and changed around:
(2 ohms)^2=2v/1A
and this is clearly NOT Ohm's Law with Ohm's Law the resistance (of
course) comes out in units of ohms squared:
ohms^2=volts/amperes
which is clearly not coming out in units of ohms!!
the law that for any circuit the electric current is directly proportional to the voltage and is inversely proportional to the resistance.
This is not about semantics. It's about believing what other people tell
you for once in your life and, even if holding this in reserve for a while,
trying to find out exactly why many people, many websites, several
books, and many universities are saying this too. That's what this is all
about.
Let us a take a piece of pure silicon. At 25 degrees , let us assume that the number of mobile charges is 1 billion (i have just chosen an arbitrary number). Suppose i apply a potential difference across its ends , then a current will begin to flow and that current will be V/R . Now suppose , i apply a voltage large enough , such that this ratio V/R exceeds 2 , then the current flowing will be 2 amperes. A current of 2 A is 2C/s.But the amount of charge in the piece of silicon is less than 2 coulombs . So what will happen? Will the current be limited to the maximum supported by the semiconductor? That implies that the resistance of the semiconductor will dynamically change to suit the voltage applied.
I guess taking sides with red herrings on the left and straw men on the right is how this subject is settled ...
To be clear, OHM's LAW is still applicable to dynamic and AC circuits which includes non-ohmic materials such as semiconductors.
If you don't think Ohm's Law is applicable then someone will have to explain away the term IMPEDANCE, juxtaposed to the term RESISTANCE.
Inductive and Capacitive Reactance in a dynamic circuit is always quantitatively expressed in OHMS. That's not a mistake.
MOSFETs, a popular nonohmic semiconductor device, have ratings in ON Resistance which is identified in the datasheets in terms of OHMS.
So what do you do with those OHMS, ignore them because OHMS LAW doesn't apply to dynamic or non-ohmic materials. If this is where the discussion finally landed and where some may have landed with it, you are more lost than you can imagine.
The OP is right here...
I have been following this discussion quite closely, I did not respond because i did not want to get in the way of more knowledgeable ppl expressing their opinions.
Both Mr.AL and Sceadwian are offering excellent arguments and i dont know which argument to take.
I feel that Sceadwian's argument is correct, although i dont know why. (actually Sceadwian's argument was what i had in mind when i posted this topic).
But now after seeing Mr.AL's argument , even that is also very hard to ignore.
I was thinking about a thought experiment yesterday night , and let me describe it to you. Maybe it will throw some light on why i am not understanding ohms law.
Let us a take a piece of pure silicon. At 25 degrees , let us assume that the number of mobile charges is 1 billion (i have just chosen an arbitrary number). Suppose i apply a potential difference across its ends , then a current will begin to flow and that current will be V/R . Now suppose , i apply a voltage large enough , such that this ratio V/R exceeds 2 , then the current flowing will be 2 amperes. A current of 2 A is 2C/s.But the amount of charge in the piece of silicon is less than 2 coulombs . So what will happen? Will the current be limited to the maximum supported by the semiconductor? That implies that the resistance of the semiconductor will dynamically change to suit the voltage applied.
I think this example shows that ohms law works for only a few range of values and not more.
EDIT : @Tesla , the first image says that the VI curve of a semiconductor is non ohmic. Is that true? I thought that the VI curve of semiC is linear when temp. is held constant.
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