Inductors Definition and 131 Threads

We know that all machines or devices working on AC have high value of time constant so that there is n damage to inductor while current reversal & high value of time constant means increase in time to reach steady state as we can see in fans , coolers , etc. but the tube-lights also have a...

Homework Statement The switch has been open for a very long time, and then we close it. In the instant right after we close the switch, assuming that...

Homework Statement Explain what is happening in the following four circuits: I don't know how to draw the circuits, but they're really really simple: (a) Current source connected in a loop with an inductor (b) Current source connected in a loop with a capacitor (c) Voltage source connected in...

In the attached figure, a de-energizing RL circuit is drawn (left switch is opened while right switch is closed). In the drawing the voltage induced in the inductor is put to be negative so that the math works out. However, that would be against Lenz's law, wouldn't it? The inductor should be...

Homework Statement For the circuit below, if L=2.0 H, emf=10 V, R1=10 ohms, R2= 20 ohms, what is the current through each component a) at the instant the switch is closed b)a long time after the switch is closed c) If after a long time the switch is reopened, what is the time constant...

How does an inductor works? I know that it stores energy in form of magnectic fields, and all the effects it does to a circuit, but i don't know how it really, physically works. The electrons go through the coils and induce a magnectic field. Why it is stored? Why doesn't the magnectic field...

First of all..I want to be clear about steady state..what actually it means..?? Does it mean state of constant current flowing across..? In my book..its written that in steady state current in inductor and voltage in capacitor is zero , hence energy consumed is zero fotr both in steady...

Homework Statement An 85 mH solenoid inductor is wound on a form 0.80 m in length and 0.10 m in diameter. A coil is tightly wound around the solenoid at its center. The coil resistance is 8.1 ohms. The mutual inductance of the coil and solenoid is 27 µH. At a given instant, the current in the...

three inductors in-series, of increasing inductance , say 1μH , 10μH and 100μH , wire-gauge constant and wire has some resistance which is constant per unit length. Is it possible to make the middle inductor, (10uH), the hottest of the three by adjusting the frequency of the AC passing...

phasor diagrams: what happens @ R=0? when R=0 and there is only the inductive impedance, what's the angle?

Hi guys, I'm pretty sure this has been answered somewhere around here. So, consider a pure inductance (zero resistance) connected in series to a battery. We know that the magnitude of the induced voltage across the inductor is given by E=L\normalsize\frac{di}{dt}. According to KVL...

Homework Statement A coil with an inductance of 2.0 H and a resistance of 10 ohm is suddenly connected to an ideal battery with E = 100 V. At 0.10 s after the connection is made, what is the rate at which: (a) energy is being stored in the magnetic field, ans: 2.4*102 (b) thermal energy...

Homework Statement an electromagnet is operated at 50A. assuming an inductance of 100H for the magnet's coil, what voltage will be developed when the switch is opened? when it is closed? assume that the switch requires 1 millisecond to operate. Homework Equations I(t) =...

Hello, first post here, my passion is electric motors, wind turbines, etc ... yes i am very boring ! I've been testing coils for my motor design for a couple of years now. I've written my own software to predict inductance, etc as well as the physical properties of the coils. I've...

Recently got hired at a local electric utility and unfortunately my college did not offer a lot of power classes so I am struggling with some things that really come down to how capacitors and inductors interact. I think I have some ideas but am really looking for some reassurance that I am...

After (partially) completing my goal of understanding capacitors, I'm onto inductors, even after reading the wiki article and doing a little more research, they make no sense to me. Currently what I'm thinking is that they are the "opposite" of capacitors, allowing DC to pass through but...

A 20.0-mH inductor is connected to a standard electrical outlet (ΔVrms= 120 V; f = 60.0 Hz). Determine the energy stored in the inductor at t = (1/180) s, assuming that this energy is zero at t = 0. Now when i tried to solve it, this is what i did: ω = 2∏ f = 2∏(60.0/s) = 377 rad/s XL =...

Hello everybody, First of all I want to thank you all for this great forum. My question is if a superconductor inductor is charged with a certain voltage and then it is open circuited what will happen. My very basic understanding tells me that if the inductor is not a superconductor (it...

Recently, I've been decapsulating chips and finding inductors printed on them, and I would appreciate some help in understanding their design. I'm used to inductors that look like this: http://imageshack.us/a/img209/4336/dsc015454.jpg A circular coil of wire- the most basic geometry...

Homework Statement Please check the attachment to see all the variables Homework Equations Xl=2*pi*f*l, Xc=1/2*pi*f*c, variation of ohms law The Attempt at a Solution Ok for 5) i found Xl & Xc, then i combined the resistances in parrallel and used ohms law to find I=v/r. My...

I have two inductors and a capacitor in series, in the order of inductor, capacitor, inductor. I'm not sure if the equation L1+L2+k*√(L1*L2) will work in this case or not, given the inductors are separated (or offset) electrically from each other by a capacitor. So I guess my question is, can...

[/itex]Hi I am new here :smile: I know (correct me if wrong please :smile:) that inductors store current in its magnetic field, and capacitors store voltage in its electric field But, why when disconnecting a inductor charged from a DC circuit, a spark is produced at the disconnected...

What type of software? Hello everyone, I'm looking for a simple software program that I may be able to configure coils, inductors, transformers, core selection etc. Basic ic availability, selection of switches, LEDs, types/strenghths/shapes of permanent magnets. I'm aware that there is a lot...

I'm trying to understand the qualitative relationship of voltage and the a.c. through a pure inductor. My books says that to maintain the current in the inductor, the voltage across the inductor provided by the a.c. supply must be equal to the back emf but in the opposite direction. I'm quite...

How to add inductors in series/parallel?? I was curious about this subject after it came up on my last physics test. However my teacher never covered this topic, and it wasn't in my book. Basicly I am wondering how inductors get added together when they are in series or parallel. My best...

Homework Statement A coil with zero resistance has its ends labeled a and b. The potential at a is higher than at b. Explain why the two following statements are consistent/correct with the situation. a) The current is increasing and is directed from a to b. b) The current is decreasing...

Hi I have been researching pulsing Electromagnets (inductors) and I have run into a problem. I have been using this formula for figuring out how fast a current will rise if powered with a ceratin voltage and the coil inductance. L (uh> / V = Time to 1 amp ( in MicroSecond) According to...

Homework Statement I attached a picture of a sample problem that I was confused about. What I don't understand is why the V2 voltmeter would read 0 volts (according to the answer key). This is because I thought that an inductor produces an induced emf and current. So wouldn't the voltmeter...

Homework Statement http://img207.imageshack.us/img207/3756/24134024.jpg N.B: (0+) means just after switch is open, and (0-) means just before switch is open. I have the solutions for this, but there are some problems I have with understanding how inductors and capacitors work in...

The question states that the circuit has been connected for a very long time. I'm assuming that then, the current will remain constant and thus the voltage for the inductor is vL = Ldi/dt = 0. Thus, using nodal analysis, I was able to solve (a) by eliminating all of the inductors from the...

"why are inductors preferred over resistors in reducing current in an AC circuit?" The quoted question from a recent exam has caused a little dilemma regarding it's interpretation and answer. 1) what does 'reduce' refer to? 2) inductors are preferred as the impedence is dependent on the...

i'm given a circuit that contains a 15 volt battery and a resistor that has a power rating of 1/4 watt and a resistance that must be greater than 1 kohm. I'm told that no matter how i set it up, i cannot exceed the 1/4 watt power rating of the resistor. this makes sense. i work out the max power...

Homework Statement Find the h parameters of the following systems:- ---L---------C-- : : R : : ---------------- L= j5 ohm C=-j5 ohm R=1 ohm Homework Equations The above questions has to be solved manually as well as simulated...

Confused about voltage induced across inductors :( Hi, As you may have gathered from the topic title, I'm rather confused about inductors :rolleyes: I have another topic going regarding boost converter design, which involves an inductor, but as this confusion/question/observation is really...

Homework Statement Quick question. If you were to find the Thevenin's equivalent circuit between the terminals of an inductor, and thus calculated the time constant using Rth, would the time constant be same as if you were to not? Same question for capacitor circuits

Referring to the attached image, find the equivalent inductance. L1 = 2 + 2 - 2 = 2H L2 = 1 + 2 - 2 = 1H L3 = 3 - 2 - 2 = -1H Leq = 2 + 1 - 1 = 2H Just checking to see if I got the concept right.

How to build a DC-->AC converter using resistors capacitors and diodes (no inductors) I have been trying to learn electronics (I am familiar with the principles, just have no experience designing complex circuits to fulfill purposes), so I went to RadioShack, got myself: breadboard assorted...

Homework Statement A security alarm for an office building door is modeled by the circuit [below]. The switch represents the door interlock, and v is the alarm indicator voltage. Find v(t) for t>0 for the circuit [below]. The switch has been closed for a long time at t=0-...

if a pure inductor is connected to an AC voltage source! The Back emf in the inductor=Thr instantaneous AC emf! THEN How can the current flow through the inductor if the NET VOLTAGE=0? please explain

Homework Statement What is the inductance in a series RL circuit in which R = 7.0 kΩ if the current increases to one half of its final value in 26 µs? Homework Equations am i correct in assuming that i should be using the time constant equation: Tau=L/R The Attempt at a Solution...

I was thinking (and hoping) that a saturable reactor type application of an RF balun transformer could be used to tune the inductance of an RF circuit using a DC voltage much like using a varactor to vary capacitance. Any comments are most welcome. Also, as far as varactors go, I know they...

Hi there! So here's the deal. I'm restoring a friend's old Philco radio for his 1968 Mustang. This includes changing out the internals to tune FM instead of AM. The old AM internals include a set of three inductor coils with magnetic cores that move in and out of the coils as you turn the...

I understand that moving charges generate a magnetic field, but what makes an inductor energy in a magnetic field? Is it just something that is, or is there a physical reason behind it?

Hey guys, I was wondering why we can not have instantaneous voltage through a capacitor and instantaneous current through inductor?, Can you explain to me why it can't happen mathematically, and physically? I know that Voltage in a capacitor is V = C dv/dt and current in inductor is i = L...

My engineering course has told me inductors are the dual of capacitors. One of the key things it has left out so far is whether, while charging, any current passes through the inductor, and if so how to calculate the voltage or current on the other side. It would make sense to me if no current...

inductor can discharge or not?

Can all conductors be inductors and could all inductors be conductors? I get confused about this because I know that inductor can be positively charges by a conductor. Can an conductor become an inductor by losing its charge from an inductor?

if the inductor is at dc steady state, the inductor would act like a short. in this case, why would the voltage across the inductor be zero? thanks in advance.

Hi, This isn't so much of a home work problem just a request for clarification from those that are more intelligent than I. I actually just wrote the final for Basic Circuit Analysis and there was a question that left me totally stumped. I've attached a VERY crude, much less complicated...

-My professor said that if i is constant through an inductor that V=0 through the formula V=L(dv/dt) . So if an inductor is in series with a voltage source it will act like a short circuit. But if the inductor is in series with a resistor and the voltage source the inductor will not act like a...