The correct answer is: A. Active
Active transducers are self-generating transducers, which means that they do not require an external power source to operate. They generate their own power by converting one form of energy into another. For example, a microphone converts sound waves into electrical signals, and a solar cell converts sunlight into electrical energy.
Passive transducers, on the other hand, do require an external power source to operate. They convert one form of energy into another, but they do not generate their own power. For example, a loudspeaker converts electrical signals into sound waves, and a light bulb converts electrical energy into light.
Secondary transducers are transducers that measure the output of another transducer. For example, a strain gauge is a secondary transducer that measures the strain in a material. The strain gauge does not generate its own signal; it measures the signal that is generated by the strain in the material.
Inverse transducers are transducers that convert a signal from one form to another in the opposite direction. For example, a loudspeaker is an inverse transducer because it converts electrical signals into sound waves. The sound waves are the opposite of the electrical signals.
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