The unit of measure for the difference in electrical potential between two devices, the “pressure”
What is a Watt?
The unit of power consumption, V x A = W
What is the voltage and frequency of North American power?
110-120V AC, 60Hz
What is the voltage and frequency of European power?
220-240V AC, 50Hz
True or False: PSUs sometimes have features that make them compatible with both American and European power standards
True
True or False: An American standard rated PSU can work on a European supply
False - The electrical differences will destroy the computer
What components use +12V?
PCIe, HDD motors, fans, most modern components
What components use +5V?
Some motherboard components, though most use 3.3V in modern systems
What components use +3.3V?
M.2, RAM, and motherboard logic circuits
What is +5VSB?
The standby voltage for external devices like keyboards and mice
What components use -12V?
Integrated LAN, older serial ports, older PCI cards
What components use -5V?
ISA adapter cards, largely defunct
True or False: A 24-pin motherboard power connector is compatible with a 20-pin motherboard
True
What systems may require redundant power supplies?
Servers or always-on systems
What is a good rule of thumb when selecting a PSU wattage?
Full operation should only use 50% of the available power
What is the most important thing to remember about computer power?
Safety, electricity will kill you, always disconnect the device from its power source before working on it, discharge capacitors, never touch a live component