Two power supplies can deliver the same wattage to a desktop. One of them wastes less of its input as heat. Which rating distinguishes that supply?
Select an answer to reveal the explanation.
Short Explanation
Both supplies can do the same work, and one of them throws away less of what it takes from the wall. You want the higher efficiency rating. A longer cord, extra memory, and a faster network card do not change how much of the input becomes heat.
Full Explanation
Efficiency is how much of the power a supply draws from the wall becomes power the desktop can use, instead of heat. The supply that wastes less as heat has the higher efficiency rating, even when both can deliver the same wattage. A longer cord does not improve that conversion. Memory changes what the desktop draws. It does not change the supply's rating. A network adapter moves frames. It is not an efficiency rating. Exam caveat: a higher efficiency rating does not raise the wattage the supply can deliver. Size the wattage for the load, then prefer the more efficient unit. Operational check: compare the ratings on the two labels at the wattage the desktop will actually draw, and install the one that wastes less. Write the result on the ticket before you close it.