Analog vs Digital Signals Quiz

Study Notes

Analog signals are continuous, representing a constantly changing physical quantity.
Digital signals are discrete, having specific, distinct values at set points in time.
Analog systems are less tolerant to noise, but efficiently use bandwidth, and are easily manipulated mathematically.
Digital systems are more tolerant to noise, as they rely on discrete values.
Analog signals require specialized hardware for transmission, while the simple, standardized components of digital systems allow software to handle the signal.
Analog systems are less flexible to adjust once implemented, as changing one part requires changing the entire system, while digital systems are relatively easy to adjust using software modifications.
Changing an analog signal's characteristics often needs a complete system overhaul, unlike digital signals which are more easily altered.

Signals can represent various physical quantities such as sound, light or pressure.
These are often measured and converted to electrical signals by a transducer in analog systems.
Digital signals represent discrete values.
Analog signals are continuous, varying over time, with waveforms showing the fluctuations.

Noise, a fluctuating signal that is not the intended signal, is inherent in all electronic circuits.
Noise can corrupt or introduce errors into all electrical signals during transmission.
Digital signals often are less susceptible to noise than analog signals as they use discrete, fixed values; noise is less disruptive.

BCD uses a set of four-bit patterns (e.g., 0000–1001) to represent digits 0 through 9, as an alternative to binary representation of decimals.
Some bit patterns are not used in the BCD system.

Feature	Analog	Digital
Technology	Records waveforms as they are	Samples waveforms into limited numbers
Uses	Analog devices only	Computing and digital electronics
Signal	Continuous	Discrete, time-discrete
Representation	Continuous range of values	Discrete or discontinuous values
Applications	Thermometers	PCs, PDAs
Data Transmission	Susceptible to noise during transmission; write/read	Immunity to write/read cycle noise
Response to Noise	More susceptible to noise	Less affected by noise
Waves	Sine waves	Square waves
Example	Human voice, analog electronics	Computers, CDs, DVDs