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Joined: Dec 2004
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What is the DC current value that will give you the same amount of heat as 1.0 amp rms going through a 10 ohm resistor?
A).637 a b) .707 a c) 1.0 a d) 1.41 a
[This message has been edited by Cinner (edited 04-05-2006).]
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Actually it is (b).707
Roger
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I agree with NJ. If you multiply the RMS by .707 again, it becomes PMS, which should be avoided. Joe
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Oooooops, I read the question again I also agree with NJ Roger
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Shouldn't the answer be:
1/0.707 = 1.41
1.41 x .637 = 0.9 amps.
Do you agree?
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Cinner, the "rms" (which I somehow read as "AC" when I first read the question, who knows where my reading skills jaunted off to) already has the AC value equal to the DC value.
Roger
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Cinner, A few years ago, meters started coming out with the "True RMS" labels all over them. These meters give you a reading that is already the peak value X .707, or the RMS, or the heating value. If you had a less spiffy, average reading meter, you would take the displayed "average" value / .637, to get to peak, and then X .707 to get to your RMS value. Hope this helps. Joe But still avoid the PMS.
[This message has been edited by JoeTestingEngr (edited 04-05-2006).]
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And the 10-ohm figure specified is one of these pieces of data thrown in to a question which is of no significance.
Since P = I^2 x R, 1 amp DC will give the same amount of heat as 1 amp RMS AC no matter what the resistance value (so long as it's the same in both cases, of course).
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The product of rotation, excitation and flux produces electricty.
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