5.2 Video Notes LR Circuits, Kirchoff\'s Loop Rule, Inductor Behavior PDF

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Summary

Introduction to LR Circuits, Kirchoff's Loop rule, and Inductor behavior...

Description

LR Circuits: -

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Inductors are coils of width that can self-induce an emf and therefore a current. The coil is said to have an inductance L. L = NoB/I Unit of inductance is the Henry (H) Inductors in a circuit will oppose any charge in the current of that circuit. That’s why they are used in surge protectors. The inductors will slow any rapid change in the current that might happen with a power surge. Faraday’s Law: e = -LdI/dt Inductance of solenoids is L = u0N2A/l

Kirchoff’s Loop rule -

As a circuit element, inductors will oppose any charge in the current They can act like batteries to keep the current going or they can act like resistors to prevent the current from flowing. As with capacitors, it is interesting to note the steady-state behavior of inductors in an LR circuit. Also similar to capacitors is the exponential growth and decay we see in the behavior of changing circuits Voltage constant I (L acts like wire) KL rule: sum of all electric potential differences around a loop is zero

Inductor Behavior in an LR circuit: -

When current just begins flowing in an LR circuit, the inductor acts like a reverse battery, opposing the start of current down any branch it’s a part of. When the current stops flowing, the inductors temporarily act like a battery, trying to maintain the current that was present. When the current flow is constant, the inductors act like a wire and there is no voltage drop across the inductor. Behavior of LR circuits are very similar to RC circuits. In RC circuits, capacitors also can act like reverse batteries to prevent current flow or wires. Time constant for LR circuit: T = L/R...