In a four-stroke engine, what occurs immediately after the intake stroke?

In a four-stroke engine, the intake stroke is followed by the compression stroke. During the intake stroke, the engine's piston moves downwards, drawing in a mixture of air and fuel through the intake valve. Once this stroke is complete and the piston reaches the lowest point, the intake valve closes.

At this point, the engine shifts to the compression stroke, where the piston moves back up, compressing the fuel-air mixture in the cylinder. This compression is crucial as it raises the temperature and pressure of the mixture, preparing it for ignition. Once the piston reaches the top of its travel during the compression stroke, the spark plug ignites the compressed mixture, initiating the power stroke.

Understanding the sequence of strokes is fundamental in grasping the operation of four-stroke engines, as each stroke has a distinct role that contributes to the engine's overall efficiency and power generation. The exhaust stroke and idle stroke are not valid answers in this context, as they occur sequentially after the power stroke and are not directly related to the process immediately following the intake stroke.