Hello. in basic electronics i learnt that : In DC (analysis) , Capacitor lt; open switch. and inductor lt; short circuitIn AC analysis, Capacitor lt; short circuitBut i also learnt that in AC current, Capacitor 's current is i CdV/dt and Zc jXcI also learnt that when at t0, the uncharged Capacitor acts as short-circuit (why?) and after charge(t--infinite), acts as an open circuit.And at t0 , the inductor acts as an open circuit and at t--infinite , inductor acts as short circuitCan you make an explanation to these?
Read your textbook. In particular study the part about exponential charge/discharge. Trying to re-write your textbook here would be nearly impossible (and unnecessary). Doug
These descriptions are based on the very short period of time after t0. Normally, we refer to this as t 0+ (because we added a femtosecond or some other infinitesimal amount of time to pass). The key to understanding the transient behavior of inductors and capacitors is to remember which quantities must be continuous and which are allowed to change instantaneously, In a capacitor, the state of charge, and hence the voltage across the capacitor, cannot make an instantaneous 'step' change. It must follow some sort of piece-wise continuous function. But, since current in a capacitor is rate-of-change of charge, it is easy to see how the current flow into (or out of) a capacitor can change instantaneously. This is the derivative function i C dv/dt. Correspondingly, the magnetic field of an inductor, which is directly related to the current through the inductor, cannot change instantaneously. But, as soon as the current starts to the change, the voltage (as defined by the V L di/dt equation) will instantaneously adjust to reflect the change in current flow.
Think of a capacitor as an empty tank on the back of a toilet. At time 0, the water supply is turned on. The water flows quickly at first, then as the float rises, it closes the valve, slowing the rate of fill. Once the float reaches the top, the water is shut off. Same with a capacitor and current. Initially, current is high, then drops off to 0. With an inductor in a DC circuit, think of the voltage across it instead of the current through it. At time 0, the voltage across it is max. As time progresses, the voltage across it decreases (just like the water coming in slower), until the voltage across it is 0 (assuming no resistive losses).
Ben What an incredible, considerate poem, and one for a individual who has impacted maximum of in such useful, concept frightening techniques. Coming in right here countless months in the past i substitute into as uncooked as i substitute into in grade college. undesirable! LC substitute into between the 1st between countless who welcomed me right here warmly. On approximately my 0.33 poem, I remember her asserting to me (paraphrased) thinking i'm figuring you out, in basic terms save writing. words of encouragement are a particular present an em-direction has, yet LC is in the process the roof If I had a concept or prayer for her to piggyback your poem, including your permission, it could be to attach a trailer on your amazing poem, asserting To LC: You provide plenty, and you deserve greater. could plenty exhilaration and contentment come your way, and could your suited poems stay a blessing to maximum of. Bri
