Basic electronics for PC repair Which electronic component primarily stores electric charge and can release it when needed in a circuit?

Introduction / Context:
Understanding passive components is essential for diagnosing power supplies, motherboards, and peripheral electronics. Capacitors are everywhere—smoothing DC rails, decoupling noise, and timing in analog sections.

Given Data / Assumptions:

• We focus on basic component functions, not specialized variants.
• “Stores electrical charge” refers to energy storage in an electric field between plates.
• Common capacitor types include electrolytic, ceramic, film, and tantalum.

Concept / Approach:

A capacitor stores energy according to E = 0.5 * C * V^2, where C is capacitance and V is voltage. In PCs, bulk electrolytics stabilize the 12 V/5 V/3.3 V rails; small ceramics provide local decoupling near ICs to shunt high-frequency noise to ground, improving signal integrity and power stability.

Step-by-Step Solution:

Verification / Alternative check:

Visual inspection of PCBs shows many capacitors near voltage regulators and CPU sockets, corroborating their role in charge storage and filtering.

Why Other Options Are Wrong:

Diode/rectifier control current direction; resistor dissipates energy as heat and limits current; transistor provides amplification/switching but is not a primary charge storage element.

Common Pitfalls:

Confusing batteries (chemical storage) with capacitors (electrostatic storage); assuming only electrolytics “store charge” while all capacitors do so by definition.

Final Answer:

capacitor.