Tolga, I am so happy that there is at least one person who sees some sense in intuitive explanations! How many have to be brave today that can afford to discuss the behavior of the 19-century inductor and capacitor? An excellent question dual to the question about the capacitor... frankly, I had the intention to ask such a question but you overtook me:)

Here's a gift for you (the attached Flash movie) in gratitude for the wonderful thoughts!

Regards, Cyril

intuitive explanations are so important that, burying students in differential equations etc ... before they understand what they are really measuring is WRONG. I read a MATH book that explained extremely difficult terms as if they were a joke !!! see this:

http://www.amazon.com/Number-Theory-Introduction-Applications-Stories/dp/0470424133/ref=sr_1_1?ie=UTF8&qid=1378142521&sr=8-1&keywords=lively+introduction

Their technique was to use intuitive examples for the most difficult concepts. The instructors OWE this to their students. My teaching style was very close to this, but, after that book, I was 200% confirmed. The only right way to teach something is :

Provide an intuitive example that people can relate to based on the phenomenon that is happening to them every single day. Then, once they understand the building block, go ahead, and dip them in deep mathematics ! They will understand it !

I lived to see this wisdom written by someone else :)))!

Note the movie is interactive - you can move through time by the arrows). It presents the inductor's behavior through time simulatenously in two ways - Cyril's (by voltage bars and current loops) and conventional (by "ascetic" curves:)

You are right, Tolga, inductors are more difficult to conceptualize than capacitors though they are the dual of each other. The concept of energy storage in the electric field of the capacitor is easier to comprehend than the concept of energy storage in the magnetic field of an inductor though the oscillator is basically an LC circuit whereby the capacitor and the inductor alternatively exchange the energy available to them creating the oscillatory behavior that can go on for ever if no dissipation exists.

In early courses in circuits and electronics more concentration is given on capacitors, for example, when considering for example power supplies (with a simple C to filter the ripple), envelope detection circuits and simple amplifiers with ac bypass capacitors. However, later on, in advanced courses the inductors will pop out as inevitable parts of the behavior, e.g. in transmission line model (where the transmission line can be thought of as a sequence of series L's and parallel C's) or the electromagnetic wave which is thought as the result of an E (electric field) perpendicular to H (magnetic field). Trust me, at such advanced levels the students will find it even more difficult to conceptualize such concepts. Hence, a better understanding of both the inductor/inductance/magnetic field and the capacitor/capacitance/electric field at early stages would help make advanced concepts easier at late stages. Good educational issue Tolga. Thanks @AlDmour

it really isn't that difficult if you can comprehend what a MAGNETIC FIELD is ...

I think, our education system ignores the importance of MAGNETIC FIELDs early on in high school, which makes it difficult to comprehend the inductor later at undergrad ...

If you think of it like a capacitor, where energy is STORED, you won't be able to explain it. When you change the DeltaI in an inductor, the magnetic field is created which is the TENDENCY TO KEEP THAT CURRENT FLOWING. When you stop pumping current into the inductor, it wants to keep that current going. This is how you STORE energy in an inductor.

Since the energy is stored in a capacitor using an ELECTRON, it is natural human tendency to think, energy is stored an an inductor via a different particle like MAGNETRON :) , but, it is really the same electron storing the energy, this time in a different mode of operation.

To summarize, if you apply an electric field on an electron, you elevate it to a different POTENTIAL (i.e., Voltage), thereby STORING ENERGY. .

if you create a magnetic field with an electron by changing its flow rate (i.e., current), they have the tendency to stay flowing in the same NEW RATE, thereby STORING energy.

I like to thank Cyril for the nice video. Also, since we are talking about energy storage in the magnetic field which we all agreed that to some how less understood than energy storage in the magnetic field. It is helpful (as a video) if used to explain to students how the energy supplied by the battery is stored in the inductor during the interval from 1 to 3 and the proof that it is stored is coming in the interval 3-5 when the energy is gradually dissipated in the resistor. This kind of experiment is usually not conducted in laboratories. The typical alternative is to conduct the capacitor charge/discharge experiment in laboratories. I haven't done such and inductor magnetize/ demagnitize experiment in my undergraduate physics or circuits lab and I believe that you and many others haven't done such an experiment. That is why I find the interactive video by Cyril very useful. This may be one reason for having less comprehension of energy storage in the magnetic field capability of an inductor. Why do you think this is the norm (if you agree with me)?. There is one technicality reason which prevents conducting such an experiment in the lab with ease. As I believe that answering the question is some what challenging, allow me not to give the answer right now as I 'd like to find out what you think that the reason might be. Hope you don't find this disturbing to your question Tolga. I think of it in line with your basic quest. Awaiting comments. Thanks.@AlDmour.

Ismat, Cyril and I were discussing something I threw out there the other day: The interactive video is awesome, but, here is how I found that the students (and myself) learn best : My system is :

1) ASK A QUESTION to which the answer is highly unknown, unpredictable, or counter-intuitive. DO NOT ANSWER IT

2) Wait until a bunch of students answer. In the meantime, the other students' neurons are going 200 mph. :) Their brain is creating a bunch of answers based on WHAT IS IN THEIR NEURAL DATABASE. Since nothing relating to the inductor is in their database, they are likely to give the wrong answer.

3) DO NOT EVER answer. Conduct an experiment that shows the answer.

This will PERMANENTLY ADD ANOTHER PHENOMENON INTO THEIR DATABASE.

From that point on, you can ask any question related to that phenomenon, they will be able to answer it pretty accurately. They LEARNED.

In my case, here is what the experiment was that nailed the inductor to my neural net :) Imagine a DC battery, a GIGANTIC inductor connected in series, and a light bulb in series. and , let's say, a switch in series. Question: What happens when I flip the switch ? You can hear the neurons going ..... :)

If you take the inductor out of the circuit, the answer is obvious. The light bulb TURNS ON :) But, what about WITH the inductor in the middle ???. NOTE: The inductor is supposed to be so huge that (say, HENRY range), it takes a few seconds , may be 10, for things to happen ...

Drum beat .......

Ta daaaa. First few seconds NOTHING happens !!! This is the counter-intuitive part.

Why would a WIRE not let the current go through ? This is counter-intuitive. Well, it is because, it is storing MAGNETIC ENERGY during the first few seconds ... So, it is not letting the energy go to the bulb ... Then, the light bulb starts turning on slowly, and it reaches full brightness in 10 seconds.

If you did the same experiment with a capacitor, in this case, the light bulb would immediately turn on, and slowly fade away, until it completely blanks out.

Amazingly enough, I have almost never seen any circuits class do this experiment, although almost every circuits class does the CAPACITOR version of it ...

Do you agree ?

Tolga: "Imagine a DC battery, a GIGANTIC inductor connected in series, and a light bulb in series. and , let's say, a switch in series. Question: What happens when I flip the switch ?..... The inductor is supposed to be so huge that (say, HENRY range), it takes a few seconds , may be 10, for things to happen ..."

Fantastic experiment! I have always dreamed to do it! And, of course, the greatest experiment would be to charge a giant capacitor and to connect it to a giant coil!

Only one remark - experiments with giant coils are extremely dangerous...

Ismat, thank you for the interesting thoughts and suggestions! It is obvious, all we here think in the same way... and it is just vonderful! I would add that my interests go beyond the "pure" circuitry and cover methodological issues of circuitry as well. If you take a look at the TABLE OF CONTENTS > CREATING A CIRCUIT METHODOLOGY > Heuristic Tools > Carrying out Unusual Experimentsv of the Circuit Idea wikibook

https://en.wikibooks.org/wiki/Circuit_Idea,

...you will see that I have set such a sophisticated experiments. Here is a video movie presenting slow charging capacitor (through a resistor):

http://www.circuit-fantasia.com/Deboo/Slowly_charging_capacitor.AVI

(the process lasts more than 30 sec)

The attached picture represents the next experiment - slow linearly charging capacitor (by a perfect Howland current source), i.e., the so called "Deboo integrator".

Regards, Cyril

I completely agree that the experiments with giant coils are very dangerous if and only if you leave them UNLOADED. Coils can increase their voltage until they reach the same current, so, presumably the voltage can reach 10000 Volts, and this is very dangerous. You know what, Cyril, you might have just answered why inductors are not so popular in labs. The reason might be this safety concerns !!! However, in my example case, since the inductor is in series, and since it is guaranteed to dissipate its energy eventually, it is about the safest inductor experiment you can do.

The best way to prevent the danger of a large coil is to work with a device that requires a very small current to operate (and prove the point). Nothing is better than an LED. ALSO, DURING THE EXPERIMENT, REPEAT 100000 TIMES TO YOUR STUDENTS : DO NOT LEAVE THE INDUCTOR UNLOADED. IT WILL BLOW SOMETHING UP !!!

Check out the composite core I am attaching a picture of. I salvaged it from a line EMI filter. These composite cores have huge AL values (this one is about 10000 nH). Since L=AL * N^2 , where N is the number of turns, you can make a 1 Henry inductor with this guy ! The one in the photo is about 9 mH. To make a 1 Henry, you need only 300 turns. With a small gauge wire, it is doable !

Now, let's calculate how much energy this guy can store ?

E=1/2LI^2.

To light up an LED, you need only about 45 mA. So, for safety reasons, let's not go above 45 mA on the inductor. If I=45mA, E=1 mJ . So, I can store i mili Joules in this guy.

Ok, what can I do with 1 mJ ? Let's calculate:

I suggest using a 1.5V AAA battery, a series 1 Henry inductor, and a very small LED with a forward voltage drop of 1.4V, and full brightness at 30-40 mA. This LED should work fine when connected directly to the AAA battery, however, it is not a big concern, since the inductor will have a series resistance anyway. Make sure to wind the inductor from very very THIN wire, 300 turns, so, it intentionally has a large ESR. Since the L is connected in SERIES with the LED, the question becomes, HOW LONG WILL THE INDUCTOR BLOCK THE CURRENT FLOW , so, it creates the visual WOW effect I suggested . Now, When you turn on the switch, the battery is 1.5V , and the forward voltage drop in the LED is 1.4V. So, 0.1V is charging the inductor. 0.1=L*dI/dt. It takes 450 ms for the inductor to reach 45 mA, after which point the LED is at full brightness. According to this, you might want to try multiple parallel LEDs to increase the LAG time ... until you get the best visual effect !

IF you have the patience, try and let me know :)

Wonderful experiments! If only Faraday can see them (of course, he will not be surprised by the coil, but the LED:) I am so happy that you have joined all these discussions about the basic electrical and circuit phenomena! Do you like the absurd and paradoxical circuits as cascodes, dynamic loads, differential pairs?

ESR is the internal coil resistance? And if you insert a small resistor in series to the LED? Do you know Fabrizio (another "coil enthusiast":)?

ESR = Equivalent Series Resistance.

EPR = Equivalent Parallel Resistance.

Of course, modeling an inductor as an inductor and a series resistance is only ONE WAY of modeling it. There was an awesome article in EDN (Inductor modeling for the 21st century). See :

http://www.edn.com/design/components-and-packaging/4344111/RF-inductor-modeling-for-the-21st-century

If the Vf (forward voltage) of the LED is 1.4V or so (which is somehow typical), and if you only use a 1.5V voltage source, you shouldn't need an additional resistance. IF you use very thin wires, the coil will already have a resistance. 300 turns might be 20 or 50 ohms, depending on how thin the wires are. That's enough ... You can easily measure this resistance with an OHMMETER, Make sure to wait for a few seconds before getting the reading though :) since, the 1 mA that the Ohmmeter is trying to pump into the inductor will take a while to settle : )

I don't know Fabrizio. Get him to follow me, if he enjoys this hands on stuff :) We can keep discussing stuff.

Wonderful thoughts! I like them... especially "You can easily measure this resistance with an OHMMETER, Make sure to wait for a few seconds before getting the reading though :) since, the 1 mA that the Ohmmeter is trying to pump into the inductor will take a while to settle : ) " Very impressive - an instrument acting as a voltage source and an inductor acting as an integrator... If you quickly switch from ommeter to ammeter, the roles will swap - the inductor will act as a current source, the ammeter as a resistive load, right?

Fabrizio: https://www.researchgate.net/profile/Fabrizio_Ricciarelli2/

About your "... the INDUCTOR cannot stop the current flow, so, the magnetic energy will have to be immediately dissipated, otherwise, the voltage will reach a million volts until something pops on the circuit board"... The solution is to short the inductor and (if there is no internal coil resistance); the magnetic energy will not be immediately dissipated and the current will circulate forever:)

All right fellows, it seems that leaving you for a while activated the neurons at 500 mph !. It is very late and I find it necessary to be back and give my share before I have to read more of your wonderful activity intrigued partly by a secondary question by me in above !.

But before I proceed any more I like to give a short reminder of the question: In light the main question by Tolga above, Cyril attached a nice video of an experiment which shows how an inductor can be energized/de-energized in a circuit dual to capacitor charge/discharge circuit. I raised a secondary question above on why such inductor circuit is not conducted in educational laboratories...(please review above). Of course, the question is almost answered in subsequent comments of my two brilliant across the world colleagues, Cyril and Tolga. However, I have my own way of presenting the answer.

You both suggested that coils can be dangerous implicating that this can be the reason. Yes, this is a reason as safety is important. Both capacitors and inductors can be dangerous when energized but they are different on behavior. A charged capacitor can be dangerous if it is charged to a high voltage only. Care must be taken before working on electronic boards with capacitors (in TVs, laser printers, ...etc) as they might be charged to peak of the line voltage. Discharging them shall be made through a resistor and not by shortening them. Hence to be safe when experimenting with capacitors we make sure that voltage is limited to a safe value (Battery or DC supply of 5-15V is good to prove the concept. On the other hand the voltage that an inductor can generate is not related to the power supply or battery voltage but rather to the rate of change of the current e=Ldi/dt, the higher rate the current rise (or drop) the higher the emf generated. The fastest current change occurs when you disconnect a close circuit of an energized coil (breaking the circuit), hence the di/dt=infinity. Hence breaking a circuit can lead a back emf of very high voltages that can even cause the air to become conductive (breakdown) and a spark occurs at the switch terminals signalling the presence of a high voltage that caused air breakdown (air breaks typically at something like 30KV/cm). Hence even a circuit with a coil at say 1.5 volt can create instantaneous high voltage at terminals. The danger depends on the size of the coil (inductor) energy storage capability. Hence experimenting with inductors requires some careful selection of the inductor. So, though safety is a reason it can be manged and there still some other reason for not conducting the coil energize/de-energize in the video experimentally. As this comment is taking too long I will present the reason in the in the next comment. Thanks @AlDmour.

Thank you for bearing with me. I will give now my view of why the video experiment (though it explains inductors behavior) is difficult to be practically implemented. The interactive video link is provided by Cyril in the first answer above.

Referring to the video experiment. In interval 1-3 (energizing interval) the battery is connected (we need a switch to do that) while in interval 3-5 (de-energizing interval) the battery is replaced with a short circuit to allow the energy to be dissipated back in the resistor. However, at point 3, to put the short, we can do that by either:

Option 1: first disconnect the battery and then short.

Option 2: first short the battery then remove it.

Clearly, option 2 is not acceptable, because shorting it can result in its explosion. For option 1 disconnecting the battery (using a switch for example) will result in a high voltage on switch terminals because disconnecting means infinite di/dt (as explained in the previous comment v=Ldi/dt). This high instantaneous voltage will create a spark across the terminals which means that the inductor is de-energize due to that the energy is dissipated to ionize the air gap and create the spark. Hence, practically, the coil will be almost de-energiszed before applying the short. Of course, this is in line with what Tolga is saying in his question "the INDUCTOR cannot stop the current flow, so, the magnetic energy will have to be immediately dissipated" and re-iterated by Cyril. Good.

I think there might be one go around such issue by applying option 2 (of first shorting the battery) to avoid the spark but with the use of a short-circuit protected power supply instead of a battery. Hope this works and the current and voltage waveforms can be recorded/monitored and get easily curves like those in the video. Thanks. @AlDmour.

Wonderful explanations Ismat !!! I agree ... Let's go back to the main question. We got side-tracked.

You completely invalidated my idea that the reason for not teaching inductors is SAFETY. Because, I do a lot of work with SUPERCAPACITORS on a research project. We work with 3000Farad (attention : FARAD, not microFarad !!! )

We use Maxwell 3000F. Check this out:

http://www.maxwell.com/products/ultracapacitors/docs/datasheet_k2_series_1015370.pdf

Almost every student of mine that just started working with supercapacitors (supercaps for short) accidentally short-circuits the two terminals. Oh Boy !!! fireworks there :) This concept (as Ismat mentioned above) is identical to OPEN-CIRCUITing a charged inductor.

However, I am still not giving up on my SAFETY issue. There is a giant difference between OPEN-circuiting an inductor vs. short-circuiting a capacitor: a short circuited supercap will have sparks flying, reminding you that, there is a lot of energy stored in it. but, this will only scare you, however, an open-circuited inductor will potentially reach 1000 Volts and will kill you !!! HIGH-AMPERAGE doesn't kill you if the voltage is only 2.7Volts like a supercap, however, 1000 Volts will !!!

So, SAFETY is a major concern., The bad thing is that, the inductor doesn't even have to be HUGE to have safety concerns. a 100 uH inductor (which is half the size of what I showed in the picture above) charged up to 2 A (which is very possible with the one I showed above) will reach 200 Volts if you stop the 2A current flow for even a microsecond by unplugging it. V=LdI/dt = 100E-6 * (-2)/(1E-6) = -200 V.

And, this is enough to cause a lot of damage from this little 1 inch inductor !!

You got a node at 200 Volts trying to dissipate 2 Amps into something !!! Not pretty !!!

So, yes, we are keeping the SAFETY as a bullet item when it comes to education.

I mentioned this in my comments above as : DO NOT LEAVE AN INDUCTOR UNLOADED. Its gotta dissipate its current into something, it better not be YOU :(

Ismat and Tolga, IMO a backward biased diode connected in parallel to the voltage source (and inductor) is a simple solution of the problem with the safety disconnection of the voltage source (the trick is widely used in transistor switching circuits). Only, if the inductor is a "superinductor", the diode should be a "superdiode":)

Regards, Cyril

Cyril, this is possibly a very good idea for the inductor experiments in the lab. It is heavily used in the transistors turning on relays ... They are called SNUBBERs. Also, MOSFET transistors have this backwards-diode built into them ...

Thank you Tolga. No, I didn't try to say that inductors are safe but rather can be managed. I agree with you as well that they can be more dangerous than capacitors when I said that in a circuit with capacitors we can limit the voltage by limiting the power supply but a circuit we can't guarantee a limit on voltages in a circuit with inductors. What I was saying in short is that experimenting (like in the video) to show magnetizing-demagnetizing cycle can be difficult as well as I argued above.

I had experienced myself the danger of inductors early as I was fond of electricity and communication at school time reading some books and doing some experiments. I tried to replicate the Hertz famous experiment of first communication by creating/receiving sparks across a small air gap. For that I used transformers salvaged from bells and radio sets in a step up mode (6 to 220 instead of 220 to 6). To attain the necessary high voltage I cascaded the transformers with the first primary connected to a battery pack (4x1.5V) and a switch. The switch I used at the time was hand made from metallic strip and a nail all fixed onto a wooden plate. The experiment in books was described like this without a warning. I assumed that at the battery side (of 6V) I can do switching on and off safely. To my surprise I found that I was receiving a shock whenever I break the switch !. To manage, I had to use wooden piece to make the switching!. Hence, it was easy for me to comprehend the fear from inductors in educational laboratories at later times.

I liked the huge capacitors technology, apparently a new technology, or it is so because I have been for long cutoff from the business of electronic components. The largest "electrolytic" capacitor that I ever come across it was probably 33000 microF. Hence, it is impressive to see that a 3000F is possible at such a relatively small weight. Thanks. @AlDmour.

supercapacitors are , believe or not , going back to 1960's. however, they made them big and cheap lately, so, talk surfaced about supercapacitors being BATTERY-KILLERS.

anyways, I like Cyril's idea of the backwards snubber diode SOLDERED on the inductor which will largely eliminate all of the safety concerns.

I should try that Hertz experiment some time :)

Yes, Cyril, connecting a "back emf diode" across a transistor switching circuit (driving a relay coil) will help to absorb the back emf generated by the coil when it switches off the relay (moving from saturated transistor to cutoff ). Capacitors (or an RC series circuits) are used as well to damp the high transient voltages that can be generated at mechanical switch terminals, commutator of a dc machine,...etc. Of course, we can't use them to make our video experiment safer as they will distort the RL circuit characteristics that we are after !.

Going again to the main question above, yes, we can say that safety is the main reason for purposefully ignoring inductors in addition to some practical limitations on the experiments. The bulkiness of inductors needed to achieve a certain filtering operation compared to capacitors makes the resort to capacitor filtering and other jobs a more viable option for industry and education as well. Thanks.@AlDmour

Amazing stories that bring us back to the romance of the past...

Here are my stories from 70's... I remember how as a boy in the technical school I drove my classmates to keep both hands on the leads of the rising coil of a transformer and, at the same time, I connected/disconnected a battery to its primary winding... the effect was striking:)

I remember also how other boys deeply impressed girls:) by charging a capacitor from the power outlet and then touching it to them:) But sometimes the desired effect did not work; you can guess why:) Nice stories from nice times...:)

See also the new question below asked specially about the time behavior of the inductor and capacitor:

https://www.researchgate.net/post/How_do_inductor_and_capacitor_oppose_input_voltage_sources_Can_we_consider_them_as_time-variable_voltage_sources

Intriguing question. Thx for it.

I agree with your postulate, perhaps because I experienced the feeling myself some time ago. (a) and (b) seem good reasons to me.

In any case, I would like to see a broad study at secondary and higher education levels to confirm the hypothesis. Also, I wonder if introducing high education electricity courses and labs, together with diff equations, complex numbers, etc. in secondary schools would change the picture. In a way, both cap and ind are "invisible", and they probably are not intuitive for people without the basics; from another perspective, introducing them with some level of sophistication in second school seem a straighforward way to universalize BOTH "high" math and physics education.

That's rough talk to me, my friend, Tolga. I can't have a say to it! Sorry

I agree exactly with Ceryl Mickov

Inductors have always been very important to me, sort of in parallel with capacitors, so I reckon there has always been some sort of resonance in my experience, and I have never seen the one as more important as the other. I often work with high voltages, not at work, but at home, as I restore old WW2 transmitters etc. as a hobby (not that I get much time for it nowadays).

Anyway, in these old transmitters, which of course is 100% vacuum tube technology, you find beautiful variable capacitors on ceramic stand-off insulators, sometimes vacuum variable or fixed capacitors, and of course variable inductors, switchable inductors and things such as variometers (tuneable circuit with a rotating inductor inside an inductor). Now these all have to work together, and not one of them is allowed to be more important than the other (else it won't work of course), no matter what they teach at university.

A particular important inductor, which is always smaller than the rest, and with a value of about 2-3 mH, is the anode choke, which allows high voltage dc to get to the rf output tube, without rf going into the power supply, so it acts as an rf resistor having a high impedance. Just next to the rf choke, is a capacitor, which allows rf to find its way to the antenna via the final resonant circuits, this capacitor acts as a dc block, so that you don't electrocute yourself when you touch the antenna. If any of these two, capacitor or choke goes faulty, there is a serious safety issue. One of these transmitters for instance runs 7500 volts and the power supply can deliver this at 2 amps.....

So safety is a major issue, and functionality is a major issue, and both capacitor and inductors are of equal importance.

Yes these supercaps are amazing....and I am sure they will replace batteries at some stage, but can they take 7500 volts? You would probably have to stack 1000 in series....and then it is no longer small...today it has become difficult to find high voltage capacitors.

Dear all

will the inductors allow AC to pass through ? if not when? - we include in equivalent circuits analysis - why both capacitors and inductors ? - my ignorance please be pardoned--

A quick way is to calculate the impedance, for a capacitor the equation is 1/2*pi*f*c and for an inductor 2*pi*f*l where f is frequency, c is capacitance and l inductance. So you can see that for high frequencies you need smaller values and components and for low frequencies larger values and components (physically). As example a 100 Mhz rf signal will easily move through a 3 pF capacitor, but a 10 kHz signal will see a high impedance (resistance). So placing capacitors and inductors in certain parallel/series configurations, you can make low-pass, high-pass and band-pass filters, and basically decide what you want to let through.

For the initial question: Dear Tolga, you have to read Tesla's work and then you will understand the reasons...

Nice stories, Ludwig! Thank you for the romantic explanations!

It might be related to understanding of complex numbers math which student might or might not have before taking that class.

@Tolga, what if we could work together for free energy projects and not fight each other like idiots who consuming all world weapons and making fight games? Have you thought about geopolitical aspects of energy?

Demetris, is it possible? I think not...

Cyril, yes it is, but human race is not ready for it now, I think. You see, we have first to over satisfy some decades of families who, although they have billions, they want to play with us, say: " Lets cut the wages in Bulgary, Greece and other countries, to see how they are going to survive..." We have many many years to suffer untill they will have been satisfied...

Interesting explanation by all!

@Tolga Soyata , As per my knowledge the inductor behaves like a resistor .This statement I can prove it in series contact of LCR circuit, in this Ckt the peak of the curve is not getting exactly narrow broadening.

@Demetris, in response to your question : "we could work together for free energy projects and not fight each other." This thinking won't work for humans, cats, mice, tigers, dogs or any other species. It is an eye-watering and UNrealistic idea. Here is a script from Dr. Susan Blackmore's book, "Consciousness, an introduction, Section 5, Evolution." PAGE 209:

"Imagine there is a population of rats living off human rubbish in a huge modern city - let's say New York. Outside every food store and restaurant and plenty of dustbins plenty of nice rat food. Every night when the workers leave, there is a chance that the dustbins will not be properly sealed, or food will be left on the ground. As long as the rats wait quietly until the humans have left, they will have it all to themselves. The best strategy FOR THE GOOD OF THE SPECIES is for every rat to wait, but will they ? Of course not. If just one rat has genes that incline it to jump in first, causing the dustbin lid to clatter to the ground and the humans come running to close it, that rat will still be better off than the rest, running off with some nice rotting meat or a discarded sandwich. That rat will get fatter, take more food home and produce more offspring who will inherit the JUMP FIRST tendency. The patient rats will lose out. Note that, this general point is not a recipe for unadultered selfishness. There are many reasons why cooperative and altruistic behaviors can thrive alongside selfish ones (Ridley 1996, Wright 1994. "

@Tolga, you should read also some other game theoretical books, the opinions are dichotomous: there is no agreement that cheating is the best evolving strategy. If you have not time for reading, then think about my version of the story you just mentioned:

"After so many centuries of fattening the generation of that mouse has controlled all NY City and thus has strangled all other mice: they cannot even find a piece of food. The success was so absolute that the fat-mice-generation finally died all together, due to its miserable life..."

If you put in the place of fat-mice some dozens of families you will end up with our world of today...

Demetris , of course. Look at how the sentence above ends ... "There are many reasons why cooperative and altruistic behaviors can thrive alongside selfish ones (Ridley 1996, Wright 1994" ...

Game theory is good at explaining things as a very simple starting point, i.e., WORST CASE, with ultimate selfishness. However, Clearly, evolution developed the human brain to think far beyond the SELF, which is much more beneficial in the long run. Otherwise, we wouldn't genetically inherit things like EMPATHY, RESPECT, which, I don't many other species have ,,,

I am not a story teller. I like to explain using equations. L the inductance of circuit can be given as," variation of flux with variation of current (L=do/di)". Means the coil wound on metal would have higher inductance than the same coil wound on wood. As flux developed, is praposnal to current for same inductor, we can say inductor is a current sensitive device. Voltage induced in inductor can be given by V=do/dt = (do/di)(di/dt) means Ldi/dt, means with same variation of current, the voltage induced would be more for the coil on metal than the same coil on wood. In inductive circuit, when voltage applied, current will not flow immediately, first flux(magnetic field) will developed then current will establish, and as flux is praposnal to current, or current will lag the applied voltage.

Capecitor of circuit can be given as C=dq/dv, or capacitance of circuit means variation of charge with respect to variation of voltage (voltage sensitive). Voltage appear, in capacitance thus given as variation of charge with variation of time as, I=dq/dt=Cdv/dt. We can say that when voltage applied,"voltage will not appear immediatly for capacitive circuit, first current will charge circuit then voltage will established, or current will lead the voltage.

If we see the flow of current to voltage(circuit/component), in inductive circuit it is after, while in capacitor it is before, or we can consider L and C are counter behaving component of circuit.

Dear Tolga,

Both the capacitor and inductor are basic elements of electric circuits. Both are reactive elements in the sense that in the capacitor i=C dv/dt while in the inductor v=-L di/dt. Notice the role of v and i are reversed in the the two components. This is because the physical nature of both elements where the capacitor reacts its changes by developing electrostatic field the inductor reacts by changing its magnetic field. The electrostatic field is created by the electric charges stored in t he capacitor. NOT only electrons are stored but also an equal positive charges must be also stored in it. The magnetic field in the inductor is created by the current flowing in it. The electric field stores energy and also does the magnetic field as formulated above in the question.

Consequently, it is very important to notice that the energy is stored in the capacitor as a potential energy while the energy stored in the inductor is kinetic energy.

Ihe analogy to the mechanical system the capacitor is analog to the spring and the inductor to the flywheel or in general to a moving mass. The L-C circuit is similar to the sprig mass oscillator system.

This from the principle point of view.

From the application and technological point of view, there is electrical systems where the inductors are basic building blocks for them. We can name many such classical systems: electrical magnets, electric machines,filters and oscillators.

ALL transmission lines are modeled by distributed L-C networks. In the electromagnetic waves bot fields are associated and the existance of one is a must for the existence of the other.

No way,In any course of the electric circuit the inductor must be well studied.

CONSIDERING digital electronic circuits thought to implement logic circuits and sytems, they are built using electronic switches and digital logic gates like CMOS technology. Indeed the integrated circuits are composed of mostly electronic devices and to less extent integrated resistors and capacitors. Because of the large area requirement of of a small inductor it is completely avoided as an integrated element. If it is necessary it added off chip. Only at very high high frequencies it became feasable to integrate it on the chip in the integrated radio frequency circuits.

In the extreme view, in the computer soft ware engineering, an electric engineer specialling in computer science may come up without powerful foundations in electrical engineering.

Lastly, the teachers must understand deeply the lessons to be able to simplify, demonstrate and explain them to satisfactory level.

Thank you Tolga for your question.

computers are capacitive so much of the health effects of electromagnetic radiation need to be remedied with inductors, especially because of what software can do to people in their own homes. I have a one to sixteen Henry wheel I have covered in magnets that I put between twenty and a hundred volts on the core of which is common. I have too much of the energy burning up in a half watt resistor it's an old Variac the power supply I have not tested the amperage of it I leave it on and off for twelve or now I can do two four and eight hour cycles also I have never considered this dangerous and have been doing this for years connected to an antenna. since it takes bad energy out of the air I put a piece of nuclear material in it's a steel box with an open end facing southeast where much of the electromagnetic radiation comes from. I could have healed the cancer of hundreds of people by taking this out of the air. the antenna is also connected to a scanner so it passes every frequency on receive. these could be sold as a vampire machine this type of device there are people who do this religiously and people might need them in every room to protect them from cancer . i think people are teying ro do something to everyone by having computers as being built with only one type of component, which is ridiculous and pathetic unless someone is trying to pass an agenda of vested interest upon other people. if something could feed us all of our memories reprocessed as being fake that would be a computer with software and wifi and trying to live near it and I think it's something they have been trying to force on everyone for a long time with the radio waves that fill the air. the radio, wifi, and everything unhealthy a computer does for hundreds of other people hardwired in our house automatically and over and over relentlessly millions of times like a goblin with rabies. this is something these people believe in amd inductors challenge that paradigm and yes you will find electricity doing other things as if it were finding ground. and anything that isn't staked I to the ground with it's own wire should have inductors. #induction#induction chemotherapy

Magnetic remanence stores magnetism, perpetually, and was used for the design of computer core memory from 1955 to 1975.

https://commons.wikimedia.org/wiki/File:KL_CoreMemory.jpg

Inductor the current device component, in series to load and carry full load current of circuit needs consideration as load current would be affected, while capacitor the voltage device in parallel to voltage, with lower charging current needed less consideration….