Comd 5070 Exam 1 Week 4 (Digital Systems) Questions And Answers

Using the Nyquist Frequency to Determine Sample Rate {Ans: Sample at twice the rate of the highest frequency in the signal. If you want data up to 100 Hz - sample at 200 Hz. If you want data up to 5 kHz - sample at 10 kHz. The sample rate for compact discs/mp3 is 44.1 kHz which means it stores signals up to 22,050 Hz (upper limit of hearing).}Digital Signals: Unknown Points {Ans: There are 'unknowns' between the points. Each number represents a very specific point in time, and you don't have any record of what occurred between one number and the next number. If you make those individual samples close enough together in time, it is almost as if the signal were continuous (like a movie; made of a series of frames).}How Can Numbers Represent Signals? Analogy Explanation {Ans: This is reflective of the level of detail that we have available in a recording system to record the amplitude of sounds. You could have a very crude system where any kind of sound gives you a maximum voltage, and no sound gives you an absence of voltage. But that system wouldn't allow us to represent sound