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Why measurement of resistance of electrode is accurate in ac not in dc?
Wiki User
∙ 11y ago
Assuming you are talking about an earth (or ground) electrode, then applying d.c. results in electrolytic action which separates charges within the soil, giving a false indication of resistance.
Wiki User
∙ 11y ago
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What is the resistance of an inductor called?
The resistance of an inductor is generally referred to as the series resistance, sometimes noted as RL. Note that resistance is a DC measurement and that an "ideal" textbook inductor has an RL of 0. The reactance of an inductor is an AC measurement which measures the reaction of a component's current flow to an alternating voltage and is frequency dependent and directly proportional to the inductor's inductance, measured in Henrie's. The impedance is most commonly used when talking about inductors or capacitors and is a combination of resistance and reactance.
What is meant by the equivalent impedance of a parallel ac circuit?
This is similar to "equivalent resistance", but impedance is a more accurate concept in the case of AC.The equivalent resistance (or equivalent impedance) means that if you replace all the resistances under consideration with one equivalent resistance, the result on the circuit will be the same.This is similar to "equivalent resistance", but impedance is a more accurate concept in the case of AC.The equivalent resistance (or equivalent impedance) means that if you replace all the resistances under consideration with one equivalent resistance, the result on the circuit will be the same.This is similar to "equivalent resistance", but impedance is a more accurate concept in the case of AC.The equivalent resistance (or equivalent impedance) means that if you replace all the resistances under consideration with one equivalent resistance, the result on the circuit will be the same.This is similar to "equivalent resistance", but impedance is a more accurate concept in the case of AC.The equivalent resistance (or equivalent impedance) means that if you replace all the resistances under consideration with one equivalent resistance, the result on the circuit will be the same.
Is resistor an ohmic device in ac circuit?
Well, yes, sort of. "Ohm" is a measurement of resistance, so I would say yes. Although I'm not sure of 'ohmic' is really a word
When to use dc welding machine and ac welding machine?
Dc welding can be used for non consumable electrodes with consumable electrode heat is transferred from electrode to work by molten metal. Ac welding is desirable for aluminum and magnesium, because it helps break up oxides AC is more stable than Dc.
How do you find the ac resistance of a diode?
The ac resistance of a diode is found using the equation: (The change in Vd)/(The change in Id) An easier was is to use the Equation: 26mV / Id. This is a general form as the ac resistance of a diode change as the temperature changes.
Why resistance doesnot depend on frequency of ac?
Because Resistance is material property...
What is the opposition to the current flow?
resistance is the opposition to the flow of electric charge
What is ac resistance of a diode?
ratio of ac voltage applied across the diode to the ac current flowing through it
What is the total opposition to a current flow in an AC circuit with both resistance and reactance?
Resistance
What is a difference between DC and ac resistance and expline DC resistasce?
DC is just direct current into a resistance it is a linear function. AC if the resistance is non reactive it would be the same linear function.
Ac voltage applied across a load resistance produce alternating current?
The reason an AC voltage applied across a load resistance produces alternating current is because when you have AC voltage you have to have AC current. If DC voltage is applied, DC current is produced.
What is the formula to calculate AC resistance if the DC resistance is known?
AC resistance is the term used to describe the elevated value of resistance due to the reduction in a conductor's effective cross-sectional area due to the the skin effect caused by an alternating current. The skin effect describes how AC current tends to flow towards the surface of a conductor, rather than being distributed across the entire cross-sectional area as is the case for a DC current.For 50/60 Hz supplies the skin effect is not great and, so, there will not be a great difference between the DC resistance and AC resistance of a winding. Accordingly, it will be very difficult to calculate the winding's AC resistance, as its value is likely to be masked by experimental error and the accuracy of the instruments.In theory, by using a wattmeter and an ammeter, the resistance of a load -in this case a winding- the readings can be inserted into the equation: R = P/I2. Using a DC supply will reveal the (DC) resistance value, and using an AC supply will reveal the AC resistance value. As explained, a combination of experimental error and instrument accuracy is very likely to mask any actual difference between the two resulting values.So, at mains' frequencies, the difference between AC resistance and actual (DC) resistance would be very difficult to determine with any degree of accuracy.
