The correct answer is: A. Passive transducers.
A piezoelectric transducer is a device that converts mechanical energy into electrical energy or vice versa. It is a passive transducer, which means that it does not require an external power source to operate. When a mechanical force is applied to a piezoelectric material, it generates an electric charge. Conversely, when an electric voltage is applied to a piezoelectric material, it will deform.
Piezoelectric transducers are used in a wide variety of applications, including:
- Ultrasonic sensors
- Loudspeakers
- Microphones
- Inductive proximity sensors
- Accelerometers
- Gyroscopes
The main advantage of piezoelectric transducers is that they are very efficient. They can convert a large amount of mechanical energy into electrical energy or vice versa. However, they are also relatively expensive.
Here is a brief explanation of each option:
- A passive transducer is a device that converts energy from one form to another without the use of an external power source.
- An inverse transducer is a device that converts energy from one form to another in the opposite direction of a direct transducer.
- A digital transducer is a device that converts an analog signal into a digital signal or vice versa.
- A pulse transducer is a device that converts a continuous signal into a series of pulses or vice versa.