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| 1.
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IIR filters |
| | A) | use feedback |
| | B) | are sometimes called recursive filters |
| | C) | can oscillate if not properly designed |
| | D) | all of the above |
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| 2.
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A Blackman window can eliminate ripple in FIR filters. The tradeoff is |
| | A) | larger transition bandwidth |
| | B) | smaller transition bandwidth |
| | C) | a non-linear phase response |
| | D) | possible instability |
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| 3.
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The output of two digital filters can be added. Or, the same effect can be achieved by |
| | A) | adding their coefficients |
| | B) | subtracting their coefficients |
| | C) | convolving their coefficients |
| | D) | averaging their coefficients and then using a Blackman window |
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| 4.
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The letter Abelow indicates the filter
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| | A) | stopband |
| | B) | transition band |
| | C) | passband |
| | D) | ripple |
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| 5.
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A DSP convolves each discrete sample with four coefficients and they are all equal to 0.25. This must be a |
| | A) | low-pass filter |
| | B) | high-pass filter |
| | C) | band-pass filter |
| | D) | band-stop filter |
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| 6.
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The inverse Fourier transform |
| | A) | converts from the frequency domain to the time domain |
| | B) | converts from the time domain to the frequency domain |
| | C) | converts from the phasor domain to the magnitude domain |
| | D) | is used to make real-time spectrum analyzers |
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| 7.
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This is the impulse response for
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| | A) | an IIR highpass filter |
| | B) | an FIR bandpass filter |
| | C) | an IIR lowpass filter |
| | D) | an FIR lowpass filter |
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| 8.
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Coefficient symmetry is important in FIR filters because it provides |
| | A) | a smaller transition bandwidth |
| | B) | less passband ripple |
| | C) | less stopband ripple |
| | D) | a linear phase response |
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| 9.
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This time graph shows the
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| | A) | frequency response of an IIR filter |
| | B) | amplitude response of an IIR filter |
| | C) | impulse response of an IIR filter |
| | D) | none of the above |
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| 10.
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Curve A is the
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| | A) | phase response of a lowpass filter |
| | B) | amplitude response of a lowpass filter |
| | C) | both of the above |
| | D) | none of the above |
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| 11.
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This windowed sinc FIR filter has ripple caused by
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| | A) | non-symmetrical coefficients |
| | B) | Gibb's phenomenon |
| | C) | too few taps |
| | D) | a defective accumulator |
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| 12.
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Two digital filters can be operated in cascade. Or, the same effect can be achieved by |
| | A) | adding their coefficients |
| | B) | subtracting their coefficients |
| | C) | convolving their coefficients |
| | D) | averaging their coefficients and then using a Blackman window |
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| 13.
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A DSP convolves each discrete sample with four coefficients and they are all equal to 0.25. This must be an |
| | A) | IIR filter |
| | B) | FIR filter |
| | C) | RRR filter |
| | D) | All of the above |
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| 14.
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This frequency response graph is for a
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| | A) | lowpass filter |
| | B) | highpass filter |
| | C) | bandpass filter |
| | D) | bandstop filter |
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| 15.
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The letter C below indicates the filter
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| | A) | stopband |
| | B) | passband |
| | C) | transition band |
| | D) | ripple |
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| 16.
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A quantizer operates at a sampling frequency of 16 kHz. What is its Nyquist limit? |
| | A) | 4 kHz |
| | B) | 8 kHz |
| | C) | 16 kHz |
| | D) | 32 kHz |
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| 17.
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Curve B is the
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| | A) | phase response of a lowpass filter |
| | B) | amplitude response of a lowpass filter |
| | C) | both of the above |
| | D) | none of the above |
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| 18.
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After point D (as frequency is increasing)
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| | A) | the phase response is linear |
| | B) | the phase response is non-linear |
| | C) | the stopband is infinite |
| | D) | the Nyquist limit has been exceeded |
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| 19.
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The letter B below indicates the filter
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| | A) | stopband |
| | B) | passband |
| | C) | transition band |
| | D) | ripple |
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| 20.
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If a linear phase filter has a phase response of 40 degrees at 200 Hz, what will its phase response be at a frequency of 400 Hz (assuming that both frequencies are in the passband of the filter)? |
| | A) | 35 degrees |
| | B) | 40 degrees |
| | C) | 45 degrees |
| | D) | 80 degrees |
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| 21.
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Which of the following is used to alter FIR filter coefficients so they smoothly approach zero at both ends? |
| | A) | rectangular window |
| | B) | Blackman window |
| | C) | Laplace window |
| | D) | Hilbert window |
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| 22.
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Point C is called
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| | A) | a phase reversal |
| | B) | the half-power point |
| | C) | a phase discontinuity |
| | D) | a phase wrap |
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| 23.
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A DSP convolves each discrete sample with these coefficients: -0.25, -0.25, 1.0, -0.25, and -0.25. This must be a |
| | A) | low-pass filter |
| | B) | high-pass filter |
| | C) | band-pass filter |
| | D) | band-stop filter |
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| 24.
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The basic process that's going on inside a DSP chip is |
| | A) | quantization |
| | B) | MAC |
| | C) | logarithmic transformation |
| | D) | vector calculations |
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