What is the function of a power supply unit (PSU)?

• A. To manage the cooling of the computer
• B. To convert electrical power for computer components
• C. To store data permanently
• D. To connect external peripherals

Answer: (B)

The function of a power supply unit (PSU) is to convert electrical power from an outlet into usable power for the computer's components. It takes the high-voltage AC (alternating current) from the wall outlet and transforms it into low-voltage DC (direct current) that the computer's hardware – such as the motherboard, CPU, graphics card, and storage devices – requires to operate. This conversion is essential because different components require specific voltage levels, and the PSU ensures that each component receives the appropriate power supply to function correctly and safely.

In relation to other options, managing the cooling of the computer is the role of fans or cooling systems, not the PSU. Storing data permanently is a function of storage devices like hard drives or solid-state drives, while connecting external peripherals is handled by input/output ports, such as USB or HDMI. Thus, the correct answer highlights the PSU's critical role in powering all the internal components essential for the computer's operation.