Question Detail
Inductive reactance is calculated by
Options
- Option A: $2\pi fL$
- Option B: $\frac{1}{2\pi fL}$
- Option C: $2\pi fC$
- Option D: $\frac{1}{2\pi fC}$
Correct Answer
$2\pi fL$
Solution & Explanation
{"type":"technical","methodBadge":"Concept & Principle","explanation":"Inductive reactance ($X_L$) is the opposition offered by an inductor to the flow of alternating current. It is directly proportional to both the frequency of the supply and the inductance of the coil.","workingPrinciple":"When an AC voltage is applied across an inductor, it produces a changing magnetic field that induces a back electromotive force (EMF) according to Lenz's Law. This back EMF opposes the change in current. The opposition, quantified as $X_L = 2\\pi fL$, increases as the rate of change of current (frequency) or the magnetic storage capability (inductance) increases.","diagramSvg":"Inductor (L)$V = I \\cdot j(2\\pi fL)$","keyFormulas":["$X_L = 2\\pi fL$ тАФ Formula for Inductive Reactance in ohms ($\\Omega$)","$V_L = I \\cdot X_L$ тАФ Ohm's law equivalent for inductive circuits"],"keyPoints":["Inductive reactance is measured in Ohms ($\\Omega$).","It is directly proportional to frequency ($X_L \\propto f$).","For DC circuits ($f=0$), $X_L = 0$, meaning an ideal inductor acts as a short circuit.","The current in a pure inductor lags the voltage by $90^\\circ$."],"advantages":["Useful for filtering high-frequency noise in circuits.","Essential for energy storage in magnetic fields."],"disadvantages":["Causes phase lag between voltage and current.","Not suitable for blocking DC current in power electronics without considering resistance."],"applications":["Tuned circuits and oscillators.","Power supply smoothing filters.","Ballasts in fluorescent lighting."],"comparisonTable":[{"feature":"Reactance Type","option1":"$2\\pi fL$","option2":"$\\frac{1}{2\\pi fC}$","label1":"Inductive ($X_L$)","label2":"Capacitive ($X_C$)"}],"additionalInfo":["In a DC circuit, frequency $f = 0$, so $X_L = 0$.","Option B represents the reciprocal, which is the formula for Capacitive Reactance ($X_C$).","Option C is dimensionally incorrect for reactance.","Option D is the correct formula for Capacitive Reactance ($X_C$)."],"answer":"A is correct тАФ The inductive reactance of a coil is mathematically defined as the product of $2\\pi$, supply frequency, and inductance.","correctedOptions":["$2\\pi fL$","$\\frac{1}{2\\pi fL}$","$2\\pi fC$","$\\frac{1}{2\\pi fC}$"],"coreConcepts":["Electromagnetic Induction","AC Circuit Theory","Frequency dependence of passive components"],"crossTopicTip":"Always remember: Inductive Reactance ($X_L$) increases with frequency, whereas Capacitive Reactance ($X_C$) decreases as frequency increases. This inverse relationship is frequently tested in filter design questions."}
Question (Hindi)
рдкреНрд░реЗрд░рдХ рдкреНрд░рддрд┐рдШрд╛рдд (Inductive reactance) рдХреА рдЧрдгрдирд╛ рдирд┐рдореНрди рджреНрд╡рд╛рд░рд╛ рдХреА рдЬрд╛рддреА рд╣реИ