In the four-step compression cycle, which step comes after Expansion?

In the four-step compression cycle, which step comes after Expansion?

• A. Intake
• B. Compression
• C. Exhaust
• D. Expansion

Answer: (A)

In a four-stroke engine cycle, the stages occur in a fixed order: intake, compression, expansion (power), and exhaust. After the expansion stroke, the piston pushes the burnt gases out through the exhaust valve during the exhaust stroke. This clears the cylinder so the next cycle can begin with a fresh intake of air-fuel. So the step that follows expansion is exhaust, not intake—the latter would occur at the start of the next cycle.

In a four-stroke engine cycle, the stages occur in a fixed order: intake, compression, expansion (power), and exhaust. After the expansion stroke, the piston pushes the burnt gases out through the exhaust valve during the exhaust stroke. This clears the cylinder so the next cycle can begin with a fresh intake of air-fuel. So the step that follows expansion is exhaust, not intake—the latter would occur at the start of the next cycle.