HORTICULTURE

Detailed explanation-1: -Exhaust Stroke Inlet valve remains closed and exhaust valve is open.

Detailed explanation-2: -During the expansion or power stroke, the high-pressure combustion gases expand moving the piston down and delivering the power. The gases expand completely, the exhaust valve opens, and the gases are expelled out during the exhaust stroke.

Detailed explanation-3: -The inlet valve remains in the closed position. The exhaust valve opens, the piston moves from BDC to TDC due to the energy stored in the flywheel. The burnt gases inside the cylinder go out through the exhaust valves. At the end of the stroke, the exhaust valve closes.

Detailed explanation-4: -Power stroke. The piston is at top dead center, intake and exhaust valves are both closed and the spark plug has just fired. The expansion of the ignited fuel/air mixture forces the piston down.