Which statement defines a two-stroke engine?

Which statement defines a two-stroke engine?

• A. An internal combustion engine which completes a power cycle with two strokes (up and down movements) of the piston during only one crankshaft revolution
• B. An engine with four strokes per cycle
• C. A turbocharged engine
• D. An electric motor with pistons

Answer: (A)

The defining idea is that a two-stroke engine completes the entire power cycle in two piston movements within a single turn of the crankshaft. In operation, one up-and-down movement combines the essential steps—intake/charging and compression, followed by ignition and power—with the other movement handling exhaust and scavenging to prepare for the next cycle. As a result, there is one power stroke per crankshaft revolution, which is shorter than a four-stroke engine’s cycle that requires four strokes over two revolutions. The other options describe different concepts (forced induction, electric motors, or a different stroke count) that don’t define the two-stroke cycle.

The defining idea is that a two-stroke engine completes the entire power cycle in two piston movements within a single turn of the crankshaft. In operation, one up-and-down movement combines the essential steps—intake/charging and compression, followed by ignition and power—with the other movement handling exhaust and scavenging to prepare for the next cycle. As a result, there is one power stroke per crankshaft revolution, which is shorter than a four-stroke engine’s cycle that requires four strokes over two revolutions. The other options describe different concepts (forced induction, electric motors, or a different stroke count) that don’t define the two-stroke cycle.