I NEED 2 KNOW WHETHER THE RESISTANCE IN AC AND DC, ARE SAME R DIFFERENT....IN AC V R DEALIN WID PHASE ANGLE N SAYIN TAT BOTH WERE IN PHASE(CURRENT N VOLTAGE)....COULD ANYONE SUGGEST THE REASON BEHIND THIS? IN DC V R SAYIN TAT BOTH WERE HAVIN LINEAR RELATIONSHIP ! SO JUSTIFY ME WHETHER THE RESISTANCE IN AC AND DC, ARE SAME OR NOT?
WHETHER THE RESISTANCE IN AC AND DC, ARE SAME R DIFFERENT....
Mar 23, 2008
9 Replies
Could you repeat it in English, please, and don't S H O U T
John
Two reasons:
- Skins effect for individual conductors. See formatting link
- Proximity effect for bundled conductors. See formatting linkboth cases the resistance increases with frequency due a reduction in effective cross-sectional area for conduction.
If you meant the resistive component of an arbitrary impedance, then this is the same for DC or AC. But I suspect you might be struggling with the distinction between pure (ohmic) resistance and reactances.
AC HAS UTERNATING CURRENT AS WEL AS DC HAS DIRECT CREENT.THEY R NOT SAME
One way of looking at it is that dc is simply very, very slowly changing ac. Unless you are going to explain the difference between dc and ac with a frequency of
0.000000000000000000000000000000000000000000000000000000000000000001 Hz?-- Sue
As when studying Fourier. Any repeating waveform can be reduced to the sum of an infinite number of sin and cosine waves.
And with a sufficiently warped mind, *anything* can be considered a repeating waveform, including the Big-Bang.... :-)
daestrom
It appears that you are confused between resistance and impedance. The Impedance for DC is the resistance but for AC it includes the effect of inductance or capacitance (hence the phase angle) If, in AC the phase angle is 0- that implies resistance only and this will be somewhat higher than the DC resistance depending on frequency.
The voltage current relationship is treated as linear in both cases.
ok frnd we know that Rdc=1.6*Rac....if this is true means , resistor's resistance value while considering na why we are taking the value of resistance multiplied wid 1.6....it remains the same in dc and ac na.....there no change will com or what?
Do you not mean Rac =1.6Rac which is possible due to skin effect as mentioned by someone else?. For AC the current tends to flow in the outer part of the conductor while it is uniformly distributed through the conductor for DC. This means that the effective area of the conductor is smaller for AC than it is for DC so that the AC resistance is higher than the DC resistance and the difference is frequency and conductor size dependent.
It might be a good idea to rephrase your question so that at least some of the rules of English apply. frnd, wid, com can be guessed at but na is a mystery so try to avoid word short cuts.
ok friend....thanks for your kind specification ,surely i will rectify it friend...
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