Linear Circuits 1 - 25 - Inductors, Part 1

Introduce inductors and their time-varying effect on current, guided by Ohm's law, Kirchhoff's laws, and differential equations; compare exponential decay and rise to final values in resistor inductor circuits.

Leverage a water-hose analogy to explain inductance: current cannot start or stop instantly, causing a lag in electrical circuits. Recognize how inductance can both enable and slow circuit behavior.

Explore how an inductor's core permeability, turns, cross sectional area, and core length determine inductance using L = μ N^2 A / l formula, with an iron-core example.

Explore how inductors resist current changes, using V = L di/dt, in a 12 nH inductor parallel to 4.7 kΩ; initially open, then behaves as a short.

Analyze a first resistor-inductor circuit as the source turns on; the inductor starts as an open circuit and current rises toward its final value, while the voltage drops to zero.

Learn how an inductor's magnetic core and inductance L oppose changing current, with v = L di/dt causing a voltage that slows current rise and prevents instantaneous changes.

Explore a second resistor-inductor circuit as the switch closes; the inductor initially resists current with a voltage drop, then settles as a short in steady state.

When current tries to fall, the inductor resists by producing a voltage that keeps the current flowing, acting like a battery to maintain its previous value.

Examine an inductor with two resistors after disconnecting the source, where current decays to zero with negative dI/dt and negative inductor voltage, approaching a final time constant.

analyze a resistor-inductor circuit where the inductor goes from open to short, with voltage across it decaying from 12 volts to zero as the current rises to 120 million amps.

Learn how current through an inductor creates a magnetic field that resists changes, making it look like an open circuit at first and a short circuit later.