Digital signals

• What are the two types of signals discussed?

  Analog and digital signals
• What does a microphone do?

  It converts sound into an analog electrical signal
• How is the voltage of an analog signal characterized?

  It can have any value within a range
• What does the graph of voltage against time for an analog signal look like?

  It shows continuous voltage values
• Through what medium can an analog electrical signal travel?

  Copper wires or coaxial cables
• What happens to an analog signal before it reaches a loudspeaker?

  It is amplified to become stronger
• What type of signals were used in past television broadcasts?

  Analog signals
• What is a digital signal compared to an analog signal?

  A digital signal is discrete, using ones and zeros
• What does the term "binary" refer to in digital signals?

  Two possibilities: one or zero
• How is a digital signal represented in terms of voltage?

  High voltage represents one, low voltage represents zero
• How can digital signals be transmitted through fiber optic cables?

  As pulses of light representing ones and zeros
• What is the function of an analog to digital converter?

  It changes an analog signal into a digital signal
• What is the advantage of storing digital signals in a computer?

  Digital information can be stored as ones and zeros
• What is the role of a digital to analog converter?

  It converts a digital signal back to an analog signal
• What principle allows light to travel through fiber optic cables?

  Total internal reflection
• Why are fiber optic cables preferred over copper wires?

  They are cheaper and lighter
• How often does a signal need to be boosted in fiber optic cables?

  Less often than in copper wires
• What does "broadband" mean in the context of digital signals?

  It carries lots of information simultaneously
• What is the typical speed of a broadband signal?

  100 megabits per second
• How does noise affect analog and digital signals differently?

  Digital signals are easier to filter from noise
• Why is it difficult to filter noise from an analog signal?

  It's hard to distinguish noise from the signal
• What happens to a digital signal when it picks up noise?

  It remains recognizable as ones and zeros
• What is the main advantage of digital signals over analog signals?

  They can carry more information and resist noise