Question

Which of the following is not an actuator?

• A. Hydraulic actuator
• B. Digital actuator
• C. Pneumatic actuator
• D. Electric actuator

Hint:

An actuator generates physical movement, while "digital" refers to control signals rather than a physical mechanism.

Answer 1

The Correct Option is B

Step 1: Defining Actuators
An actuator transforms energy into motion. Common actuator types are:
- Hydraulic actuators (1): generate movement via fluid pressure,
- Pneumatic actuators (3): generate movement via compressed air,
- Electric actuators (4): generate movement via electric power.
The term "digital actuator" (2) does not describe a physical actuator type. "Digital" relates to control signals, not motion generation itself.
Step 2: Conclusion
Therefore, a digital actuator is not classified as a physical actuator type.
Final Answer: \[ \boxed{\text{Digital actuator}}\]