Chapter 4 Flashcards
The superposition principle states that, in linear systems, the net response caused by two or more signals is the sum of the responses that would have been caused by each stimulus individually.
True
Suppose that two sinusoidal waveforms are added together. The first has a frequency of 8000 Hz, and the second has a frequency of 7,893 Hz. The summed waveform will show an alternating constructive and destructive interference pattern, known as βbeatsβ. What is the beat frequency in Hz?
107Hz
Suppose two acoustic waves, Wave A and Wave B, have the same amplitude and frequency. These two waves cross paths and, at a given instant, Wave A is raising the pressure by 38πππ, and Wave B is also raising the pressure by 27πππ. What is the local pressure in πππ at that instant?
65πππ
Consider a waveform made up of the following sinusoidal frequencies: 150 Hz, 301 Hz, 452 Hz. This complex waveform would best be described as being _____ (periodic, aperiodic, or quasi-periodic)
periodic
Wave A and Wave B have the same amplitude and frequency. These two waves cross and at a given instant, Wave A is raising the pressure by 15πππ, and Wave B is also raising the pressure by 15πππ. What is the local pressure in πππ at that instant?
30
Two sinusoidal waves whose amplitudes and frequencies are identical are 180 out of phase. Their interference would be ___
completely destructive
Peak clipping is not desirable because the sharply cut-off corners contain _____ frequency components, similar to _____ waves.
high, square or rectangular
When two sinusoids of different frequencies are added together, this results in _________ .
constructive and destructive interference
In a linear system, adding together two sinusoidal waveforms of the same frequency but different phases will result in the creation of a second frequency that was not present in the original waveforms. (T or F)
false
Suppose that two sinusoidal waveforms are added together. The first has a frequency of 3000 Hz, and the second has a frequency of 2500 Hz. The summed waveform will show an alternating constructive and destructive interference pattern, know as βbeatsβ. What is the beat frequency in Hz?
500Hz
Fourierβs theorem says that any periodic waveform can be written as the sum of a series of sine and cosine waveforms. (T or F)
True
Consider a waveform made up of the following sinusoidal frequencies: 200 Hz, 401 Hz, 602 Hz. This complex waveform would best be described as being (periodic, aperiodic, or quasi-periodic)
quasi-periodic
Consider a waveform made up of the following sinusoidal frequencies: 400 Hz, 800 Hz, 1200 Hz. This complex waveform would best be described as being (periodic, aperiodic, or quasi-periodic)
periodic
Consider a waveform made up of the following sinusoidal frequencies: 111 Hz, 349 Hz, 513 Hz. This complex waveform would best be described as being (periodic, aperiodic, or quasi-periodic)
aperiodic
Composed of a harmonic series; regular repeating cycles
periodic
Contains no repeating cycles
aperiodic
Composed of a nearly harmonic series
quasi-periodic
A Fourier series is a harmonic series. Which of the following frequencies does NOT belong as part of the harmonic series shown below?
150 Hz, 300 Hz, 450 Hz, 500 Hz, 750 Hz, 900 Hz
500
Adding sinusoids of the same frequency (phases can be the same or different) always results in a waveform that is the same frequency (phase may vary). (T or F)
True
