MODEL EXAM III DTSP PART B

The DFT is preferred for

1. Its ability to determine the frequency component of the signal.

2. Removal of noise.

3. Filter design.

4. Quantization of signal.

• 1, 2 and 3 are correct

• 1 and 2 are correct

• 1 and 3 are correct

• All the four are correct

What is the value of x(n)*h(n), 0≤n≤11 for the sequences x(n)={1,2,0,-3,4,2,-1,1,-2,3,2,1,-3} and h(n)={1,1,1} if we perform using overlap save fast convolution technique?

• {1,3,3,-1,1,3,5,2,-2,2,3,6}

• {1,2,0,-3,4,2,-1,1,-2,3,2,1,-3}

• {1,2,0,3,4,2,1,1,2,3,2,1,3}

• 1,3,3,1,1,3,5,2,2,2,3,6}

The rst six points of the 8-point DFT of a real valued sequence are 5, 1 − 𝑗3, 0, 3 − 4𝑗, and 3 + 𝑗4. The last two points of the FFT outputs are respectively

• 0, 1 − 𝑗3

• 0, 1 + 𝑗3

• 1 + 𝑗3, 5

• 1 − 𝑗3, 5

If the discrimination factor ‘d’ and the selectivity factor ‘k’ of a chebyshev filter are 0.077 and 0.769 respectively, then what is the order of the filter?

• 2

• 3

• 5

• 6

If s=σ+jΩ and z=rejω and r=1, then which of the following inference is correct?

• Imaginary axis in the s-plane is mapped to the circle, |z|=1

• RHS of the s-plane is mapped outside the circle, |z|=1

• LHS of the s-plane is mapped inside the circle, |z|=1

• None of the mentioned

If s=σ+jΩ and z=rejω, then what is the condition on σ if r<1?

• σ > 0

• σ < 0

• σ > 1

• σ < 1

What is the number of filter coefficients that specify the frequency response for h(n) symmetric?

• (M-1)/2 when M is odd and M/2 when M is even

• (M-1)/2 when M is even and M/2 when M is odd

• (M+1)/2 when M is even and M/2 when M is odd

• (M+1)/2 when M is odd and M/2 when M is even

The impulse-invariant design method maps the analog impulse response to the digital equivalent impulse response. It is not appropriate for the

• highpass and bandstop filter design.

• lowpass and bandpass filter design

• Low pass design

• Band pass design

Computation of the analog frequency Ω from the digital frequency ω using the frequency warping formula so that the frequency-distortion in bilinear transformation is compensated

• Spectral factorization

• Zero-phase filtering

• Prewarping

• all of the above

What is the dead band of a single pole filter with a pole at 3/4 and represented by 4 bits?

• (-1/2,1/2)

• (-1/8,1/8)

• (-1/4,1/4)

• (-1/16,1/16)