Show WHAT inductance MEANS EXPLAINED I 1 its t s cause and effects are here T told old in popular language for the novice when it ii conductor cuts a magnetic field it voltage Is induced in tile the conductor duer due r the voltage induced depends debonda for its ita milico on oil the rapidity with which tile the conductor cuts the magnetic field tho the of tho induced volt olt la in a function or of the rate or cutting not of the field density etc A conductor carrying a current la is surrounded by a magnetic ile beld ad if the value of tile the current be decreased tho the magnetic field will decrease in 11 decreasing the magnetic field about the conductor will cut the conductor mul find induce in it it 11 voltage tills this induced Indu ceil voltage tit in it a conductor caused by it a change tit in the magnetic held field which was produced by the conductor la is called uio electromotive electro motive force of self leduc tion the direction of tile the induced voltage duo due to self Is such its ai to oppose tiny any change looking fit at the end of it a conductor it if applied current Is 18 in it direction away from tile observer it 11 reduction in current will produce fill an e c tit in f of self belf induction that will add to tills current how flow away from tile observer or being the same direction as is the applied voltage an increase tit in aljo flow of the current will increase the imag riette held field and an c e m f of self in will bo be induced that will oppose tho the flow of current suppose we consider the magnetic field about it conductor carrying fin an alternating current the current alternately flows in one direction and yeo L 17 ta X ak RA EM F DUE to fig 1 then the other direction each time the direction of how flow of the current changes the direction of the magnetic field reverses when an alternating current flows in a conductor the current which Is set up by the changing magnetic field JQ J also alternating suppose that fig 1 represents a of tile the current how flow ing in the conductor during the first quarter of the cycle while ill the current Is from zero at A to a maximum value tit at 13 the magnetic field will bill build up with tile current the inductive back e in f which alch depends on the rate ot of change of low flow 1 will be it maximum tit at A whre where the flux Is changing most rapidly iud a minimum at 11 where change in flow fl 0 W Is zero similarly during tl the 1 e 0 ther other three quarters of a cycle the induced e in m I 1 due to induction will be a maximum tit nt 0 and B find and a minimum at D tho the dotted curve cuno then in fit fig 1 represents the e tit f of self induction note that there Is a phase dlf dir ference of one quarter of a cycle or GO 00 electrical degrees between the 0 in f duo due to induction and the current producing the magnetic field tills this ac tion of the conductor having a back e m f induced in it when a varying current flows through the conductor Is called relf induction in other words self induction may be defined ns as the property of an electrical circuit that tends to prevent tiny any change in the of the circuit flowing through it the e in f of self belf induction Is always in such a direction as is to prevent any change of current in the circuit A length of wire wound in the form of a coll coil called a solenoid hns has a greater self induction than tile same name length ot of straight the allf induction of a coll coil with no iron near the magnetic field Is IB a constant and depends on oil the physical dimensions of the circuit the unit of inductance Is the henry an electrical circuit has tin inductance of one henry when it a change in the current of one ampere per second will cause a back e tit f of one volt it has been explained that fin an over ever changing magnetic held field surrounds a circuit carrying tin an alternating current and that toils thle changing magnetic field induces in the circuit a back e in m f which opposes any chinigo change in the current flowing lu in the circuit if a second secona electrical circuit Is brought within the life magnetic field of the first circuit the second circuit will have a voltage induced in it the va value of the voltage induced in fit the second electrical circuit will bu be onu one volt per lilies of flux cut per second the direction of die ahe induced voltage in the second circuit will lp ile electrical degrees out ur e with the applied voltage of tit the arst first cir circuit cult the hie phenomenon just de ascribed scribed Is known as mutual inductance self induction la Is the die reaction of a B circuit upon itself mutual induct lr duct ance la Is tile the re that exists be i tin it i 1 0 i 1 i A mi 1111 lit IK field but selma titta elo li 1 nl 41 baill buill types of ined et I 1 inui tire lire founis tit ll 11 both liili high ani ii 1 an I 1 1 iii ali in irs III aph olit trall tin i bittor tin the niini a i alf am mil alili tion rhe r Is nil an of mutual the of the sity sets up nil a held field that Is cut ut hi the conductor that fornis the dm second ni avy of wo tin in fit batilo i tn fro it I 1 ency ch citi it tuning voil toll depends for fo r its notion fiction upon df belf induction tit operation of it loose loor colloer depends upon tut it induction fur for the tran fur fer of energy from tile primary or antenna circuit to tile secondary tuned circuit to tile ri reet trying alpar atus li Is l i connected skin effect euf ct Is due to solf sc lt induction in a conductor carrying direct current resistance drop which can be considered us its a bulk back voltage la is constant over faliu entaro cros section of tile con coil ductor the HIB appl lel voltage then Is in opposed nt it tiny any point on oil the cross soc bee tion of a conductor by the alie same back voltage and hence the current flowing lol ng itself evenly over the cross of tile conductor ton ductor tills Is riot not true in fit conductors var crying tilter tintIng current ur rent there tire are two to voltages hint oppose the alie flow llo of alternating current ur rent tit in it conductor first tho bick back voltage title dna to resistance and second tile nick hack voltage in deuced by telf induction the magnet le lc field surround surrounding ing tile conductor will be strongest at the center of tile conductor and weaker soaker tit at tile the surface ot of tile conductor tills this will cause the induced back p e in t f to bo be largest tit nt tho the ceriter center and smallest Rinal lest nt at tho the surface of the conductor naturally tile den sity of tile circuit that lows flows will be inversely proportional to tills opposing e tit ni f or the least current will how flow at tho the center anti and tile tho greater current will low flow along the surface an aa the frequency of tho the current Is in increased the skin effect as it Is called becomes more and more pro bounced noun ced finally nt at radio frequencies such R f small quantity of current flows near the center of the conductor that the ho conductive material there Is useless and can be remove removed for this a I reason tubing Is often used for conducting 1 high power nt at high frequencies |