🔍 Key Concepts

• Fuel oil centrifuging removes components based mainly on difference in density • Think about which listed item would be present as an impurity/contaminant in fuel oil tanks • Consider which of the choices is heavier or denser than fuel oil and tends to settle out

💭 Think About

• Ask yourself: in a fuel oil purifier, what are we trying to take OUT of the fuel — heavier solids/water, or other usable fuels? • Which option is something that would normally be found mixed in as dirt, sediment, or heavy residue rather than as a separate useful product? • Among the choices, which substance would naturally separate to the outside under high centrifugal force because of its higher density?

✅ Before You Answer

• Verify which of the listed substances is actually considered a contaminant in fuel oil rather than a different usable fuel or oil type • Check which option would have a greater density than fuel oil and would therefore move outward in a centrifuge bowl • Make sure you are not choosing something that would normally be carried as its own clean cargo/product rather than as an impurity in fuel oil