Final answer:
PSE (Power Sourcing Equipment) refers to devices that supply power through Ethernet cables, while PDs (Powered Devices) are devices that receive power in this way. Electric power, measured in watts, can be calculated with the formula P = IV.
Step-by-step explanation:
PSE (Power Sourcing Equipment) and PDs (Powered Devices) are terms commonly used in the context of Power over Ethernet (PoE) technology. PSE refers to devices such as switches and hubs that provide power through the Ethernet cable to PDs. PDs are devices like VoIP phones, wireless access points, and security cameras that receive power using this method. Electric power (P) is the rate at which energy is supplied by a source or dissipated by a device, most often measured in watts (W). The electric power supplied to or dissipated by devices can be calculated using the formula P = IV, where I is the current in amperes (A) and V is the voltage in volts (V).
For example, if a PD such as a wireless access point operates at 0.5A and is connected to a standard network voltage of 48V, it would require a power of P = IV = (0.5A)(48V) = 24W. This calculation lets network administrators understand the power demands of their PoE-enabled network devices.