Capacitors are fundamental building blocks in electronics. From stabilizing power supplies to filtering noise and enabling wireless communication, they are everywhere. To understand capacitors, we need to first answer: what is capacitance?

What is Capacitance?

Capacitance is the ability of a component or circuit to store electrical energy in an electric field. In simple terms, it is the measure of how much charge a capacitor can hold at a given voltage.

What Is a Resistor?

A resistor is a two-terminal passive component that opposes current flow. By converting electrical energy to heat, it stabilizes voltages, limits current, and shapes signals. Its value is measured in ohms (Ω), with common series like E6, E12, and E24 providing standard increments for design.

Core Functions in Real Circuits

Current Limiting: Protect LEDs, ICs, and sensors from overcurrent.

Voltage Division: Create reference levels for ADCs, comparators, and bias networks.

Bias & Stability: Set operating points in transistor and op-amp stages.

Filtering & Timing: Combine with capacitors/inductors for RC time constants and signal conditioning.

Sense & Feedback: Low-ohm shunts measure current for control loops.

Tip: For precision dividers, match temperature coefficients (TCR) and use tight tolerance pairs to maintain ratio accuracy over temperature.