#AP Physics C: E&M - Inductance Study Guide ⚡

Hey there, future physicist! Let's dive into inductance – a key concept for your AP Physics C: E&M exam. This guide will help you understand, remember, and apply the core ideas. Let's get started!

#1. Introduction to Inductance

Inductance is all about a conductor's opposition to changes in current. Think of it as inertia for electricity! Just like a heavy object resists changes in motion, an inductor resists changes in current. This is super important in circuits, especially when dealing with AC.

#2. Physical and Electrical Properties of Inductors

#2.1 Inductance and Current Opposition

• Inductance (L) is the measure of a conductor's resistance to changes in current. 🔌
• It depends on the conductor's physical characteristics.
• Straight wires have negligible inductance (L ≈ 0).
• Inductors (like solenoids) are designed for significant inductance.

#2.1.1 Factors Affecting Solenoid Inductance

• Number of turns (N): More turns = higher inductance.
• Length of the solenoid (ℓ): Longer solenoid = lower inductance.
• Cross-sectional area (A): Larger area = higher inductance.
• Magnetic permeability of the core (μ_core): Higher permeability = higher inductance.

• Formula for Solenoid Inductance:

  $$L_{\text{sol}} = \frac{\mu_{\text{core}} N^2 A}{\ell}$$