#AP Physics 2: Compound DC Circuits - The Ultimate Study Guide ⚡

Hey future physicist! Let's dive into the world of compound DC circuits. This guide is designed to make sure you're not just prepared, but confident for your AP Physics 2 exam. We'll tackle equivalent resistance, non-ideal components, and measurement techniques, all while keeping it engaging and easy to remember.

#1. Compound Direct Current (DC) Circuits

# 1.1 Equivalent Resistance of Multiple Resistors in a Circuit

Let's start with the basics. Circuits aren't always simple; they often combine resistors in series and parallel. Here's how to break them down:

• Series Connection: Think of it like a single lane road 🚗. All charges must travel through each resistor one after the other. The current is the same through each resistor.

• Parallel Connection: Now imagine a multi-lane highway 🛣️. Charges have multiple paths they can take. The voltage is the same across each parallel path.

• Equivalent Resistance ($R_{eq}$): This is the total resistance of a group of resistors, treated as a single resistor. It simplifies circuit analysis.

  • Series Resistors: Just add them up!

    $$R_{\text{eq}, s} = \sum_{i} R_{i}$$

  • Parallel Resistors: Use the reciprocal sum formula:

    $$\frac{1}{R_{\text{eq}, p}} = \sum_{i} \frac{1}{R_{i}}$$