Answer :
Final answer:
The motion of the cam is transferred to the valves through rocker arms, which depress the valve stems as part of the engine's timing system. The correct option is (2).
Explanation:
The motion of the cam is transferred to the valves most directly through rocker arms. In the context of an internal combustion engine, the camshaft is linked to the crankshaft via a timing belt or a timing chain. When the cam rotates, its lobes push against cam followers or directly against rocker arms that in turn depress the valve stems, causing the valves to open. The camshaft rotates synchronously with the crankshaft, typically at a 1:2 ratio in a four-stroke engine, meaning for every two rotations of the crankshaft, the camshaft rotates once.
This motion control and conversion ensure the engine's intake and exhaust valves open at the proper times during the engine's four strokes: intake, compression, power, and exhaust. This exact timing between valve movement and piston position is critical for the engine's operation, affecting performance and fuel efficiency.
