Red Seal Instrumentation and Control Technician Practice Exam

Which of the following is a characteristic of digital signals?

1. They represent values through continuous variation

2. They are affected by noise more than analog signals

3. They represent values through binary coding

4. They can only transmit analog data

The correct answer is: They represent values through binary coding

Digital signals are characterized by the way they represent information through discrete values, specifically using binary coding. Binary coding consists of two states, usually represented as 0s and 1s, which corresponds to the electrical states of low (off) and high (on). This binary representation allows for data to be transmitted in a format that is less susceptible to variations than continuous signals. In contrast, digital signals do not represent values through continuous variation, as seen with analog signals. They do not have a smooth range of values and instead jump between the discrete states of 0 and 1. Additionally, digital signals are generally more resistant to noise compared to analog signals; the clear distinction between the discrete states makes it easier for the receiving end to interpret the signal accurately despite some interference. Lastly, digital signals are specifically designed to encode digital data rather than exclusively transmitting analog data, which further differentiates them in function and use.