Discussion in 'General Electronics Chat' started by nikhilthunderlion, Oct 4, 2007.

1. ### nikhilthunderlion Thread Starter Member

Oct 1, 2007
23
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for dc circuit ,for a fixed resistor if applied voltage is high than current is how .but in ac circuit if ac voltage is high than ac current can be low is it true, if yes tell me how?

2. ### cumesoftware Senior Member

Apr 27, 2007
1,330
11
The Ohm's law aplies to both AC powered resistors and DC powered resistors. In principle, for a fixed resistor, the higher the voltage is, the higher the current is.

3. ### thingmaker3 Retired Moderator

May 16, 2005
5,072
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E = I*R, therefore I = E/R

4. ### ixisuprflyixi Active Member

Sep 16, 2007
52
1
It is not necessary for the current to be high in a resistor in DC or AC that depends on the resistance not the voltage, it is possible but certainly not necessary. For a resistor in a DC circuit the current could be very low depending on the resistance its the same with AC.

5. ### techroomt Senior Member

May 19, 2004
198
1
in ac or dc, the current and voltage are "directly proportional" in a fixed resistor. in other words, if voltage goes up, the current will also go up a proportional amount. if voltage were to double, the current would double. if voltage were halved, current would half.

6. ### ixisuprflyixi Active Member

Sep 16, 2007
52
1
I am not objecting to that. What I am saying is that a "high voltage" does not necessitate a high current. So, it is (possible) to have a high voltage but still a low current. It all depends upon the resistance.

7. ### cumesoftware Senior Member

Apr 27, 2007
1,330
11
Well, the point is that in a fixed resistor, the higher the potential difference at is terminals, the higher the current that biases it. Evidently, if we have a variable resistor being fed by a constant voltage, the lower the resistance, the higher the current. Again Ohm's law. Lots of possiblities, but there is no need to loose the focus here when the question was about a fixed resistor and a variable voltage.

Although being informative, you might confuse members that are new to electronics. Of course, I'm not discouraging you from doing that. Just showing the bad side of it.

8. ### ixisuprflyixi Active Member

Sep 16, 2007
52
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hmm I thought I was trying to clear up the memebers confusion. You cant please all of the people all of the time.

9. ### recca02 Senior Member

Apr 2, 2007
1,211
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the confusion of OP might be due to transformation achieved with the help of transformers where the primary may have low voltage and high current and secondary might have high voltage and low current but still the ohms law applies
it is just that the resistance is transferred to the primary as low.
one more thing though something similar can be achieved with DC as well so there shud be no controversy about AC or DC not following ohm's law.