Circuit Theory

Q1: What is circuit theory?
A1: Circuit theory is an approximation of Maxwell's equations.

Q2: What function do models serve?
A2: A model approximately represents of some aspect of the physical world.
There is often trade-off between the accuracy of the model and its ease of use.
Idealizations are often quick and user-friendly, and can give a rough idea about how a circuit behaves.

Q3: What are the idealizations made by circuit theory?
A3: Circuit theory:
1. Treats the speed of light as infinite
$c \to \infty$
2. Assumes that electrical and magnetic fields associated with individual elements do not interact with any other elements
That is, elements can only "talk" to each other through wires

Q4: Why learn circuit theory if they don't perfectly capture real circuits?
A4: For design and analysis, perfectly accurate models are not needed (or even conceivable) to still yield useful information about particular real-world circuits.