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Why in DC it is called as Resistance and impedance in AC Circuits?
Wiki User
∙ 9y ago
Resistance applies to both d.c. and a.c. circuits, and is determined by the resistivity, length, and cross-sectional area of a conductor.
In d.c. circuits, resistance is the only opposition to the passage of current. However, in a.c. circuits, the flow of current is opposed, not only by resistance, but also by reactance. Reactance is caused by a circuit's inductance or capacitance, or both, and varies with the frequency of the supply. Like resistance, reactance is also measured in ohms.
So, in a.c. circuits, the combination of resistance and reactance is called 'impedance'.
Impedance is not the algebraic sum of resistance and reactance, but the vectorial sum. So if, for example, an a.c. circuit had a resistance of 3 ohms and a reactance of 4 ohms, the impedance would be 5 ohms, not 7 ohms.
Wiki User
∙ 9y ago
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What is the opposition to the current flow?
resistance is the opposition to the flow of electric charge
Is it the impedance value same in AC and DC?
Since impedance is the vector sum of resistanceand reactance, and since reactance is a function of frequency, impedance only really applies to a.c. circuits. You could argue that, in a d.c. circuit, impedance is equal to resistance, but the term really isn't normally used in d.c.
The opposition to the flow of electrons through a conductor?
In the simplest case, that would be resistance - but there is also another type of opposition (only relevant for AC) called reactance. The combined effect of resistance and reactance is called impedance.
Why ac pass by capacitor as it has infinite resistance?
ac passes by repeatedly charging and discharging the capacitor. when you study ac circuit analysis, you will find out about impedance and reactance, which will allow you to compute how ac behaves in capacitors and inductors.
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 opposition of current flow measured in?
The opposition of current flow is measured in ohms. For DC circuits it is resistance and for AC circuits it is impedance.
What is the opposition to the current flow?
resistance is the opposition to the flow of electric charge
What does electrical impedance refer to?
It is the complex ratio of the voltage to the AC (alternating current) circuit. It extends the concept of resistance to AC circuits due to magnitude and phase.
How you can calculate ampere?
Voltage (volts) divided by Resistance (ohms). For AC circuits the resistance part of this formula is replaced by "impedance" which involves the effects of capacitors and inductors as well.
Total opposition to current flow in an AC circuit with both resistance and reactance is called?
Impedance.
Why do not you use impedance in DC circuit?
Actually, its a matter of terminology... Impedance can be used in a DC circuit. We just call it resistance, however, transient analysis would imply a different notation. To be clear, impedance is normally used in AC circuits, and it is the electrical opposition to AC, taking into account not only voltage, but phase angle. In a DC circuit, impedance and resistance are the same thing, simply with a phase angle of zero.
Is it the impedance value same in AC and DC?
Since impedance is the vector sum of resistanceand reactance, and since reactance is a function of frequency, impedance only really applies to a.c. circuits. You could argue that, in a d.c. circuit, impedance is equal to resistance, but the term really isn't normally used in d.c.
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.
What is impedance in speakers and can it be measured in watts?
Impedance in electricity is described as an opposing force to electron flow. It consists of a combination of resistance, capacitance, and inductance. This forms the actual "resistance" to electron flow in a circuit versus "pure resistance"such as a resistor added in a circuit to slow electron flow. Impedance is more prevalent in AC circuits versus DC circuits as it reacts to AC current flow much more than DC current. Current flow in a speaker circuit is considered AC so impedance is more meaningful in a speaker setup. Impedance can be measured or calculated based upon current flow so it can be converted to watts using the formula Watts = amps times voltage.AnswerImpedance is the vector sum of resistance and reactance, and is measured in ohms. No, it cannot be measured in watts, which the unit for power.
Short definition of impedance in connection with ac?
Impedance in an AC circuit is like resistance. In fact, impedance is measured in ohms, just like resistance. Impedance takes into account the fact that current and voltage are often not in phase with each other due to capacitive and inductive reactance.
What will happen in case of AC circuit for maximum power transfer theorem?
According to maximum power transfer theorem for ac circuits maximum power is transferred from source to load when the load resistance is equal to the magnitude of source impedance. The source imoedance is the thevenin equivalent impedance across the load
What is the difference between impedance and resistance?
Resistance is a concept used for DC (direct currents) whereas impedance is the AC (alternating current) equivalent. Resistance and impedance have different fundamental origins even though the calculation for their value is the same: R=V/I
