Question

Which one of the following is not a type of actuator?

• A. Pneumatic
• B. Hydraulic
• C. Solenoid
• D. Ultrasonic

Hint:

If a device generates motion or force in response to a control input, it's an actuator. If it measures or senses, like ultrasonic devices do, it's not.

Answer 1

The Correct Option is D

An actuator is a device that converts a control signal into mechanical motion or force. Common types of actuators include:
- Pneumatic actuators, which use compressed air
- Hydraulic actuators, which use pressurized fluid
- Solenoid actuators, which use electromagnetic force
All of the above are standard actuator types used to create linear or rotary movement.
On the other hand, ultrasonic refers to high-frequency sound waves and is primarily used in sensors (like ultrasonic distance sensors) or non-destructive testing (NDT). It is not an actuator because it doesn’t convert control energy into mechanical motion in the typical sense.
Thus, Ultrasonic is not a type of actuator.