What is a heat sink?

• A. A heat sink
• B. A capacitor
• C. A relay
• D. A transformer

Answer: (A)

A heat sink is a passive cooling device attached to electronic components to remove heat. It conducts heat away from the hot part into a metal base and fins, which greatly increase surface area so more heat can be carried away by natural convection (and sometimes by forced air). This keeps temperatures within safe limits and helps maintain reliability. It’s usually made of aluminum or copper and sits alongside components like CPUs or power transistors. A capacitor stores electric energy in a field, a relay is an electromechanical switch, and a transformer changes voltage and current through magnetic coupling. The heat sink’s role isn’t to store or modify electrical signals, but to transfer heat to the surrounding air.