Contents
How does reactance effect current?
Greater reactance leads to smaller currents for the same voltage applied. An ideal resistor has zero reactance, whereas ideal inductors and capacitors have zero resistance – that is, respond to current only by reactance. As frequency increases, inductive reactance also increases and capacitive reactance decreases.
How does an inductor limit current?
The effect of an inductor in a circuit is to oppose changes in current through it by developing a voltage across it proportional to the rate of change of the current. When there is a sinusoidal alternating current (AC) through an inductor, a sinusoidal voltage is induced.
What is AC reactance?
Reactance is the measure of the opposition to the flow of alternating current caused by the inductance and capacitance in a circuit rather than by resistance. Reactance is present in addition to resistance when conductors carry alternating current.
What limits current flow in an inductive circuit?
Inductive reactance is a counter voltage that limits the flow of current, as does resistance. Inductive reactance is measured in ohms.
Why there is no reactance in direct current?
What is the Role of Inductor in DC Circuit? In short, there is no frequency in DC supply i.e. frequency in DC = 0. This is the reason why inductive reactance is zero in DC power supply.
Do inductors decrease current?
In other words, inductors tend to resist changes in current. When current through an inductor is increased or decreased, the inductor “resists” the change by producing a voltage between its leads in opposing polarity to the change. To store more energy in an inductor, the current through it must be increased.
What is the value of reactance in alternating current?
Reactance is the opposition offered to flow of alternating current. This opposition may either be due to inductor (L) and or capacitor (C). The value of reactance due to inductor having inductance L is ωL whereas its value is (1/ωC) for capacitor having capacitance C. Let us consider a circuit for better understanding.
Why is the AC current not extremely large?
Note that although the resistance in the circuit considered is negligible, the AC current is not extremely large because inductive reactance impedes its flow. With AC, there is no time for the current to become extremely large. Consider the capacitor connected directly to an AC voltage source as shown in Figure 2.
How to calculate reactance in capacitive and inductive circuits?
Sketch voltage and current versus time in simple inductive, capacitive, and resistive circuits. Calculate inductive and capacitive reactance. Calculate current and/or voltage in simple inductive, capacitive, and resistive circuits. Many circuits also contain capacitors and inductors, in addition to resistors and an AC voltage source.
Since inductors drop voltage in proportion to the rate of current change, they will drop more voltage for faster-changing currents, and less voltage for slower-changing currents. What this means is that reactance in ohms for any inductor is directly proportional to the frequency of the alternating current.