CompTIA A+ Power Supply Practice

A PC Power Supply Unit (PSU) can accept the voltage of 110-120 VAC (Volts of Alternating Current), or 220-240 VAC. PSU's operation can be adjusted to the supplied voltage either with the use of a manual selector switch on the back of the device or automatically by the device. PSUs equipped with manual selector switch are referred to as fixed-input devices, PSUs offering automatic voltage adjustment are known as auto-switching PSUs.

• True

• False

Which of the acronyms listed below refers to the type of electric current supplied to most of the internal PC components?

• AC

• HVDC

• DC

• PFC

Which of the following answers refer(s) to voltages generated by modern PC power supplies? (Select all that apply)

• +/-3V

• +3.3V

• +5V

• +5.5V

• +/-12V

Modern ATX motherboards use a 24-pin power connector, however many power supplies might be equipped with a 20-pin power connector for backward compatibility with older motherboards and a separate 4-pin connector for delivering power to PCIe slots on newer motherboards. The 20+4 connector can be used with either 20- or 24-pin motherboards (in case of a 20-pin motherboard power slot, the 4-pin connector simply remains unattached to the board).

• True

• False

What is the name of a device that can provide short-term emergency power during an unexpected main power source outage?

• UPS

• PoE

• SVC

• PSU

What is the name of a device that can provide short-term emergency power during an unexpected main power source outage?

• Standby UPS

• Redundant power supply

• Dual-power supply

• Managed PDU

The term "Modular power supply" refers to a PSU equipped with detachable cables.

• True

• False

The power output rating of a PSU is based on a measurement unit known as:

• Amp

• Hertz

• Volt

• Watt