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Resistance isn't directly affected by frequency -rather, it depends upon the cross-sectional area, length, and resistivity of a conductor.
Having said that, at higher frequencies, current tends to flow towards the surface of a conductor. This is called skin effect, and acts to reduce the effective cross-sectional area of a conductor -resulting in the resistance of that conductor rising somewhat. The higher the frequency, the greater the skin effect, and the higher the resistance.
This higher resistance to the flow of AC current is termed AC resistance, and shouldn't be confused with a circuit's reactance which is something entirely different.
Additional answer:The skin depth is that distance below the surface of a conductor where the current density has diminished to 1/e of its value at the surface.
What else can I help you with?
What happens to the resistance when the frequency is doubled?
When the frequency is doubled, the resistance of a circuit remains unchanged. Resistance in a circuit is independent of frequency and is determined by the material and physical dimensions of the resistor.
What is the effect of low grid frequency?
Any equipment that is dependant upon frequency will be effected. Synchronous motors will slow down.
Why resistance doesnot depend on frequency of ac?
Because Resistance is material property...
What are 3 ways to reduce resistance?
divide frequency
Why would there be a gain when you add the emitter capacitor to a circuit board?
A capacitor has lower resistance (impedance) as frequency increases. Adding an emitter capacitor effectively lowers the emitter resistance as frequency increases. Since gain in a typical common emitter amplifier is collector resitance divided by emitter resistance, this decrease in emitter resistance will increase gain as frequency increases.
Does the resistance depend on the frequency?
Yes. The resistance does depend on frequency. The reason is 'skin effect'. When an alternating current is passed through a conductor only a small portion of the conductor, usually called the skin depth carries the current. The value of skin depth is inversely proportional to frequency. As the frequency is increased, the skin depth decreases. But the value of ac resistance is directly proportional to frequency, or in other words, inversely proportional to skin depth. Thus, at higher frequencies, ac resistance is higher. This is the reason why we multiply the dc resistance by an empirical value 1.2 or 1.3 to calculate its ac equivalent.
Does the impedance of an RL series circuit varies inversely with the frequency?
The simple answer is no. The impedance of an R-Lcircuit is the vector sum of the circuit's resistance and its inductive reactance. Resistance is determined by the length, cross-sectional area, and resistivity of the conductor (although its 'a.c. resistance' is proportional to the frequency squared), whereas the inductive reactance is directly proportional to the frequency of the supply.
What is difference between resistance and reactance while both are measured in ohms?
Resistance is constant no matter the frequency applied. Reactance varies depending on the frequency of the power applied to it.
How do you increase amperage without changing voltage or resistance?
You cannot increase amperage without changing voltage or resistance. Ohm's law states that voltage is current times resistance. You cannot change one alone. Not even changing frequency in a capacitive or inductive circuit will do this, because changing frequency represents a change in reactance, which is effectively a change in resistance.
How frequency decreases when resistive load is added to the circuit?
Resistance does not change frequency. Frequency cannot be changed without very sophisticated equipment, often called Variable Frequency Drive, or VFD, which is used in motor starters today.
How many ohms in MHz?
You can't mix apples and oranges nor resistance and frequency.
Can 50 Hertz multi tester be used on 60 Hertz 220 volts for testing voltage?
Any of the multi testers that I have come across are not frequency sensitive. I use a Fluke process meter and it can be used to measure frequency if that scale is selected. Voltage is voltage, amperage is amperage and resistance is resistance regardless of what he frequency is.
