Final answer:
The correct answer is b) the plunger is connected directly to the disc of a globe valve, where the energized solenoid acts to control the flow by moving the plunger that interacts with the valve disc.
Step-by-step explanation:
The operation of a direct operating, electrically operated valve involves various components and processes. When the solenoid is energized in this type of valve, it creates a magnetic field that pulls a plunger or similar mechanism to either open or close the valve. The action of the solenoid directly impacts the plunger which in turn affects the valve's disc (e.g., in a globe valve) or plug to control the flow of fluid or gas.
Likening the solenoid in an electrical circuit to a valve in a water circuit, when the solenoid is energized and thus the valve is closed, it restricts flow in a similar manner to how a closed valve prevents the flow of water.
In the context of the question provided, the correct answer is b) the plunger is connected directly to the disc of a globe valve.