Analogue Vs Digital Waves Practice Flashcards
Define analogue and digital signals, highlighting their key differences
Analogue signals can vary in frequency and amplitude. Its signal has a strength proportional to the quantity it is representing.
Digital signals is conveyed in binary code to represent the size of the measured quantity. Digital signals are a series of pulses consisting of just two states, ON (1) or OFF (0). There are no values in between.
Explain why digital signals are less susceptible to noise compared to analogue signals.
Digital signals use binary encoding (1s and 0s), making them easier to restore to their original form after interference. Noise can be filtered without altering the data, whereas noise in analogue signals directly alters their amplitude or frequency, degrading quality.
Describe two advantages and one disadvantage of digital signals for long-distance communication.
Advantages:
1. They can be transmitted long distances without degrading in quality.
2. Digital signals can carry large amounts of information.
Disadvantage:
Conversion from analogue to digital is required, which adds complexity.
Why do analogue signals degrade in quality when transmitted over long distances?
Analogue signals are affected by noise and interference during transmission. Over time, these interferences accumulate, causing the signal to weaken and distort.
Compare the energy efficiency and data handling capacity of digital signals versus analogue signals for modern telecommunication systems.
Energy Efficiency: Digital signals require less energy because they can be transmitted with lower power while maintaining quality.
Data Handling: Digital signals can carry larger volumes of data and enable compression techniques, making them ideal for modern systems. Analogue signals have limited capacity and cannot be efficiently compressed.
Identify one natural example of an analogue signal and explain its characteristics.
Sound waves.
Characteristics: Sound waves vary continuously in amplitude and frequency, representing changes in pitch and volume.
Discuss how digital signals maintain quality when transmitted over long distances and explain the role of binary encoding in this process.
Digital signals maintain quality because their binary nature allows noise to be filtered out. Even if interference occurs, the signal can be restored to its original form (1 or 0). Binary encoding ensures clear distinction between the two states, minimizing errors during transmission.
Evaluate the advantages of digital signals in terms of data storage and quality compared to analogue signals. Use examples to support your explanation.
Advantages: Digital signals can store large amounts of data without degrading (e.g., MP3 files or high-resolution videos). Noise can be easily removed, maintaining quality.
Disadvantage:
analogue signals like vinyl records or VHS tapes degrade over time due to physical wear and environmental factors.
Analyse how noise impacts analogue signals and propose a method to reduce the effects of noise in such signals.
Impact: Noise in analogue signals changes their amplitude or frequency, distorting the original data. This leads to a loss of quality, such as static in a radio signal.
Solution: Use signal amplifiers and filters to reduce unwanted frequencies or external interference. However, this can only partially restore signal quality.
Explain why conversion is required for digital signals and discuss one potential limitation of this process.
Reason for Conversion: Digital devices require data in binary format, so analogue signals (e.g., sound) must be converted to digital (via ADC—analogue-to-digital converters).
• Limitation: The conversion process may lose some details (e.g., in audio, this is known as sampling error), resulting in a less accurate representation of the original signal.
What are the two states of a digital signal, and how are they represented?
The two states are on (1) and off (0). These binary states are represented as pulses.
What is digital sampling, and why is it necessary to convert an analogue wave into a digital signal?
Digital sampling is the process in which an analogue wave is converted to a digital signal. It is necessary because digital systems, like computers and digital storage devices, can only process and store discrete numerical data.
Explain the role of a transducer in converting an analogue signal to a digital signal. Provide an example of a transducer in this process.
A transducer converts physical signals (like sound, pressure, or light) into an electrical signal. For example, a microphone acts as a transducer by converting sound waves (air pressure changes) into electrical signals.
Describe the potential consequence of selecting a sample rate that is too low.
If the sample rate is too low, the analogue wave will be undersampled, leading to distortion known as aliasing. This results in a loss of detail and accuracy in the digital representation of the original signal.
How does reducing electromagnetic interference improve the accuracy of digital conversion? Mention one method used to achieve this.
Electromagnetic interference can distort the signal, leading to errors during conversion. Using shielded cables, such as screened cables, helps reduce this interference by preventing external electromagnetic waves from affecting the signal.
