Which component atomizes a metered amount of air and fuel?

• A. Air Filter
• B. Venturi
• C. Throttle Plate
• D. Fuel Pump

Answer: (B)

The principle being tested is how a Venturi creates a pressure drop to pull fuel into the air stream, producing an atomized air-fuel mixture. As air speeds up through the narrowed throat, its static pressure falls. That lower pressure draws fuel from the metering jets into the airstream, breaking it into tiny droplets that mix with the air. The throttle plate simply controls how much air can flow, setting the amount of fuel that can be drawn, but it isn’t the atomizer. The air filter cleans the incoming air, and the fuel pump supplies fuel, but neither causes the atomization—the Venturi does.