How many piston movements occur during a four-stroke cycle?

In a four-stroke cycle, the engine completes one full cycle of operation through four distinct strokes: intake, compression, power, and exhaust. During this cycle, the piston moves a total of four times—once for each stroke.

1. The first stroke is the intake stroke, where the piston moves down, drawing in the air-fuel mixture into the combustion chamber.

2. The second stroke is the compression stroke, where the piston moves back up to compress the air-fuel mixture.

3. The third stroke is the power stroke, occurring after the mixture is ignited, which forces the piston down due to the expansion of gases.

4. Finally, the fourth stroke is the exhaust stroke, where the piston moves back up to expel the exhaust gases from the combustion chamber.

This sequence results in four distinct movements of the piston, corresponding to each stroke of the cycle. Thus, the correct answer reflects the complete operational cycle of a four-stroke engine, showcasing how the piston movement is integral to the engine's function.