Which component converts a physical quantity like temperature into an electrical signal?

• A. ADC
• B. DAC
• C. Transducer
• D. Digital computer

Answer: (C)

A transducer is a device that converts one form of energy into another. In this context, it specifically refers to the ability to transform a physical quantity, such as temperature, into an electrical signal. For instance, a thermocouple is a type of transducer that generates a voltage that is directly related to the temperature difference it experiences. This conversion allows for temperature measurements to be used in electronic circuits and systems, enabling further processing, display, or control.

In contrast, an Analog-to-Digital Converter (ADC) can take the electrical signal produced by a transducer and convert it into a digital format for processing by digital systems. A Digital-to-Analog Converter (DAC) performs the opposite function, converting digital signals back into analog form. A digital computer processes data but does not inherently convert physical quantities into electrical signals; it relies on transducers and ADCs for that purpose. Therefore, the transducer is the correct answer as it directly links the physical world with electrical representation.