Analog output signals are typically used to drive which of the following?

Analog output signals are particularly effective for driving modulated valves because these valves require continuous control over their position or flow rate. Analog signals, which vary continuously over a range (usually 4-20 mA or 0-10 V), provide the necessary level of precision and gradation to adjust the valve's opening in a smooth manner. This allows for fine-tuning of processes in which fluid flow needs to be adjusted based on real-time data such as pressure, temperature, or flow rate.

In contrast, block valves, contactors, and lights typically operate in a binary manner, meaning they are either fully on or fully off. Block valves generally require on/off signals, contactors are controlled by discrete signals to activate or deactivate motors or loads, and lights typically respond similarly to toggle switches or simple relay contacts. Each of these applications does not require the variable control precision that analog signals provide, making modulated valves the ideal choice for utilizing analog output signals effectively.