Answer :
The rocker arm is a critical component in the internal combustion engine that is used to actuate the inlet and exhaust valves. It translates the motion from another part of the engine to operate these valves.
In the context of this question, the correct answer is:
(i) Cam and follower.
Here's a step-by-step explanation of how it works:
Camshaft: The camshaft contains lobes or cams that rotate as the engine runs. It controls the timing and operation of the engine's valves. Each cam lobe has a specific shape that opens and closes the valves at the right times during the engine's cycle.
Cam follower: The cam follower is in contact with the camshaft. As the camshaft rotates, the cams push the follower up and down. This movement is then transmitted to the rocker arm.
Rocker Arm: The rocker arm pivots on a shaft or a rocker arm stud, moving in a see-saw motion. This motion is transferred to the valves, opening and closing them. When the cam pushes the follower, the rocker arm pushes down on the valve, opening it, and then it closes when the cam lobe rotates past the follower, allowing the valve spring to return the valve to the closed position.
In this process, the rocker arm does not directly interact with the crankshaft but is directed by the cam and follower system. Therefore, choices (ii) Crank, (iii) Crankshaft, and (iv) none of these are incorrect options.
Understanding the function of the rocker arm and its relationship with the camshaft is essential for understanding how engines work and how they manage air and exhaust flow efficiently.