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While it is true that an inductor opposes the flow of an alternating current, it does not necessarily 'block it'. The quantity that opposes the flow of an AC current is the inductor's inductive reactance, expressed in ohms. Inductive reactance is proportional to the frequency of the supply voltage and, at 50 or 60 Hz, the reactance of a transformer's winding is relatively low (although very much higher than its resistance) and, while this acts to limit the amount of current flow, it certainly doesn't act to block that flow.
Wiki User
∙ 12y ago
Wiki User
∙ 13y agoAn inductor blocks AC while allowing DC because it resists a change in current. The equation of an inductor is ...
di/dt = V/L
... meaning that the rate of change of current is proportional to voltage and inversely proportional to inductance.
If you apply DC across an inductor, it will stabilize to some current flow based on the maximum current available from the current / voltage source. In this mode, the inductor presents very low resistance, so it can be said that it allows DC to pass.
If, however, you apply AC across an inductor, you need to consider its inductive reactance by integrating the above equation in terms of the circuit conditions. The equation for inductive reactance is ...
XL = 2 pi F L
... meaning that the inductive reactance is proportional to the frequency and to the inductance.
Thus, the higher the frequency, the higher the reactance. Since reactance is a phasor measure of resistance, it can be thus said that an inductor will block AC.
Wiki User
∙ 11y agoInductor will allow the ac current to flow through it....it wont block.
An inductor's reactance increases with the AC frequency. At a high enough frequency it will block the AC. For DC the inductor's reactance is zero, because the frequency of DC is zero.
Wiki User
∙ 13y agoInductors by their nature resist CHANGE in current.
Wiki User
∙ 11y agoYou have it backwards.
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What are the differences between the natures of dc flux and ac flux?
dc flux is caused by dc current (flux and current are proportional), it is a constant value. Put an inductor (or transformer winding) across a battery and you will get dc flux. ac flux is caused by ac current (flux and current are proportional), it is a moving value, the flux moves with the current, typically cyclical but the waveform is arbitrary as long as we're moving.
Why capacitor used in a DC inverter?
capacitor is component used to store and release the electric charge.and also it has feature to block the dc but bypass ac.and inverter is device which converts ac to dc and then again ac
What is a DC shunt motor?
A DC shunt motor is a motor using DC supply with the the inductor connected parallel to the armature.
Why doesnt a field coil in a DC shunt motor lead to short ciruit when it is a fact that an INDUCTOR is a short circuit to DC?
Yes, an inductor is a short circuit to dc...that's true....IF the inductor is an ideal one, that is, the inductor has no resistance but has inductance only. Anything in real world, as you know, is not ideal. An inductor is usually made of a copper wire. A copper wire has its own resistance. If an inductor coil is thin and long (i.e. many turns), it will provide an appreciable resistance to DC, and will no longer be a short circuit.
Why coupling capacitor block DC in amplifier?
capacitors at input block dc and allows ac only. so absolute none of the dc enters the circuit. They are called decoupling capacitors or blocking caps. -DANNY S
Does a Cpacitor allow ac to pass through it?
no capacitor does not allow ac component .if allow then inductor allow dc component .
Why inductor block ac and pass dc?
When your circuit starts up, your inductor creates an electrical current in the opposite direction. With dc, this effect vanished after the circuit is started. With ac, the current keeps starting and stopping so the inductor keeps creating a current in the opposite direction.
Can you charge inductor with dc voltage or ac voltage?
Inductors are low pass devices, they conduct most easily at low frequencies. DC is the limiting case for low frequency AC: i.e. DC is the lowest possible AC frequency, zero Hz and thus conducts best through an inductor. Capacitors are high pass devices, they conduct most easily at high frequencies. Infinite frequency AC is the limiting case for high frequency AC. Infinity Hz would conduct best through a capacitor.
What is the difference between coil inductor solenoid?
Physicall no difference.But inductor uses ac and solinoid uses dc.
What devices can be used to block DC and pass AC?
simple capacitor can do this job (to block dc and pass ac).
Why is an inductor called a choke?
Because it stops or chokes AC while passing DC.
If an inductor and a switch are connected in parallel through which the current will flow in an AC circuit?
A:The inductor does not allow ac signal to pass through. It blocks ac and passes dc. If the switch is open, then the ac signal wont pass. If the switch is closed, then the ac signal will pass through the switch.AnswerIt is incorrect to say that an inductor 'does not allow' the passage of an alternating current. An a.c. current will pass through an inductor, although the inductor will limit the value of that current due to the inductor's inductive reactance. Inductive reactance, which is expressed in ohms, is directly-proportional to the inductance of the inductor and to the frequency of the supply. The value of the current is determined by dividing the supply voltage by the inductive reactance of the inductor.If the switch is connected in parallel with the inductor, then closing the switch will apply a direct short circuit across the inductor, and the resulting short-circuit current will cause the circuit's protective device (fuse or circuit breaker) to operate.
Does an inductor blocks AC?
An inductor blocks AC while allowing DC because it resists a change in current. The equation of an inductor is ...di/dt = V/L... meaning that the rate of change of current is proportional to voltage and inversely proportional to inductance.If you apply DC across an inductor, it will stabilize to some current flow based on the maximum current available from the current / voltage source. In this mode, the inductor presents very low resistance, so it can be said that it allows DC to pass.If, however, you apply AC across an inductor, you need to consider its inductive reactance by integrating the above equation in terms of the circuit conditions. The equation for inductive reactance is ...XL = 2 pi F L... meaning that the inductive reactance is proportional to the frequency and to the inductance.Thus, the higher the frequency, the higher the reactance. Since reactance is a phasor measure of resistance, it can be thus said that an inductor will block AC.
Why we use the inductor?
To answer these questions I will tell you which devices or equipments are inductive.These include:TransformersHair clipers,hair blowers,motorsYou hopefully know what those devices or equipments are used for,hence why we use inductors.
Why a transformer designed for a 120V AC input will often burn out if connected to a 120V DC source?
All transformers are designed to work on AC. They do not work on DC.If you connect an inductor to DC, the current will increase until the capacity of the source or the conductance (1/resistance) capacity of the inductor and conductors is reached. Often, this condition will overheat and destroy the inductor, or destroy the source. A transformer is not an exception, as it is a form of inductor.
Does an inductor work in both ac and dc?
Depends on what you mean by work. It still opposes changes in the current flow through it, that doesn't change. But as DC has no phase, it produces no phase shifts as it does in AC.
How dc supply is applied to field coil in a brush less alternator?
Through a coupled inductor, similar to a transformer, but working on DC instead of AC.
