A carburetor's venturi increases air speed and reduces which of the following?

The function of a carburetor's venturi is critical in the process of mixing air and fuel for combustion in an engine. As air flows through the venturi, the design causes a reduction in the cross-sectional area, which in turn increases the velocity of the air flowing through. According to Bernoulli's principle, an increase in the speed of the fluid (air, in this case) results in a decrease in pressure.

This reduced pressure is essential for drawing fuel into the airstream from the carburetor's fuel bowl, allowing for the proper mixture needed for optimal engine performance. Thus, when the venturi increases the air speed, it directly leads to a reduction in pressure.

Understanding this principle is vital for anyone studying engine operation, as it highlights how fuel is atomized and mixed with air, significantly affecting engine efficiency and performance. The reduction in pressure is fundamental to the carburetor's ability to function effectively, supporting the performance characteristics of four-stroke engines.