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An AC current tends to flow towards the surface of a conductor due to a phenomenon called the 'skin effect', which acts to reduce the effective cross-sectional area of that conductor.
Since resistance is directly-proportional to the cross-sectional area of a conductor, the conductor's resistance to an AC current is, therefore, higher than its resistance to a DC current (which distributes itself across the full cross-sectional area). We call this elevated value of resistance, AC resistance.
The skin effect increases with frequency to such an extent that, at radio frequencies, there is little point in using solid conductors and tubes are used instead. At mains' frequencies (50/60 Hz), however, the skin effect is moderate and, so, the value of a conductor's AC resistance is only slightly elevated compared to its true resistance.
It's important not to confuse the term 'AC resistance' with 'reactance', which is a function of a conductor's inductance and/or capacitance, and the frequency of the supply.
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What is ac and DC resistance of a diode?
diodes follow an exponential curve meaning non linear in nature. by using Boltzmann formula an impedance can be calculated. That would be the AC Resistance the dc resistance on any device is the voltage drop divided by the dc current.
What is the different between ac dc motors?
DC Motor works on DC source and AC motor works on AC source
Can the same electric bell work on AC as well DC 250v electric supply?
No, the two systems need a different coil resistance.
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.
What is the opposition to the current flow?
resistance is the opposition to the flow of electric charge
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.
How many things can a multi meter measure?
Resistance Voltage (both AC and DC) Current (both AC and DC)
What is ac and DC resistance of a diode?
diodes follow an exponential curve meaning non linear in nature. by using Boltzmann formula an impedance can be calculated. That would be the AC Resistance the dc resistance on any device is the voltage drop divided by the dc current.
What are the three main function of the multimeter?
A typical multimeter can measure: * AC & DC voltage (volt) * AC & DC current (amp) * resistance (ohm)
What is the different between ac dc motors?
DC Motor works on DC source and AC motor works on AC source
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.
Is impedance and resistance are different?
Resistance is a concept used for DC (direct currents) whereas impedance is the AC (alternating current) equivalent. Impedance is a more general term for resistance that also includes reactance.
Can the same electric bell work on AC as well DC 250v electric supply?
No, the two systems need a different coil resistance.
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.
What is the opposition to the current flow?
resistance is the opposition to the flow of electric charge
What are the different voltages for DC?
Like AC, DC can be at any voltage.
What is the difference between DC and AC resistance?
AC resistance should NOT be confused with IMPEDANCE or REACTANCE.When AC flows through a conductor, it tends to flow towards the surface of that conductor due to a phenomenon called the 'skin effect'. The skin effect, therefore, acts to reduce the effective cross-sectional area of the conductor. Since resistance is inversely-proportional to cross-sectional area, the result is an elevated value of resistance compared with that to DC current. This is called AC RESISTANCE, and it increases with frequency. At mains frequencies (50/60 Hz), AC resistance is not dramatically higher than DC resistance but the difference becomes significant at high frequencies.Read more in the Related link shown below this answer.
