Question 716Steam Plants - Assistant Engineer

The correct answer is D) governor. Rotating flyweights, acting against a spring force, is the basic mechanism used in a mechanical governor. The governor's function is to regulate the speed of an engine or other prime mover by adjusting the fuel or power supply. As the speed increases, the flyweights move outwards due to centrifugal force, compressing the spring and reducing the fuel or power input to maintain a constant speed. The other options are incorrect because they do not describe the function of a governor. A reducing valve reduces pressure, a safety valve relieves excess pressure, and a feed water regulator controls the water level in a boiler, but none of these use the rotating flyweight mechanism of a governor.