Chapter 1 - What is a signal?¶
Quiz¶
Question 1¶
Which of the following best describes a signal?
- Any physical phenomenon that can be seen or heard
- A quantity that varies as a function of some independent variable
- Any type of data that can be stored in a computer
- A periodic waveform described by sines and cosines
Question 2¶
A digital audio file (e.g., a .mp3, .wav) is best modelled as:
- A continuous-time signal, because sound is continuous
- A continuous-time signal with quantized amplitude
- A discrete-time signal with quantized amplitude
- A stochastic signal, because all recordings contain noise
Question 3¶
For the descriptions listed below, pick the one that is most clearly a discrete-time signal in practice:
- Current output from a solar panel
- The filtered output of a DAC (Digital to Analog Converter)
- The speed of a car as a function of time
- The output of an ADC (Analog to Digital Converter)
Question 4¶
Which of the following is the best example of a quantized signal?
- Instantaneous voltage across a resistor
- A continuous-time temperature waveform
- 16-bit PCM audio samples stored on a CD
- A mathematical sine wave evaluated for all real $t$
Question 5¶
Which of the following statements is the most accurate.
- A deterministic signal must be periodic
- A deterministic signal can be predicted exactly from a known mathematical formula
- A stochastic signal has no structure
- A stochastic signal must be sampled to be meaningful