Which term best describes circuits built on a single chip and available in analog and digital varieties?

• A. IC Circuits
• B. Analog Circuits
• C. Integrated Circuits
• D. Passive Circuits

Answer: (C)

Circuits built on a single chip and available in analog and digital varieties are integrated circuits. An integrated circuit, or IC, is a compact electronic circuit fabricated on a semiconductor substrate—usually silicon—that can contain many transistors, resistors, and capacitors all integrated together. This on‑chip integration enables complex functions to be implemented in a tiny package and produced in high volume. ICs come in analog form, digital form, and mixed-signal form that combines both types of processing. That combination of single‑chip fabrication with either analog or digital behavior is what makes the term the best fit.

Analog circuits describe the type of signal processing rather than how the circuit is built, and they can be implemented either as discrete components or as ICs. Passive circuits refer to networks made only of passive components and don’t inherently imply single‑chip fabrication or digital functionality. The plural “IC Circuits” is not the standard terminology; the widely accepted term is “Integrated Circuits.”