Explore topic-wise MCQs in Digital Signal Processing Questions and Answers.

This section includes 10 Mcqs, each offering curated multiple-choice questions to sharpen your Digital Signal Processing Questions and Answers knowledge and support exam preparation. Choose a topic below to get started.

1.

What is the frequency response of the system described by the system function H(z)=\(\frac{1}{1-0.8z^{-1}}\)?

A. \(\frac{e^{jω}}{e^{jω}-0.8}\)
B. \(\frac{e^{jω}}{e^{jω}+0.8}\)
C. \(\frac{e^{-jω}}{e^{-jω}-0.8}\)
D. None of the mentioned
Answer» B. \(\frac{e^{jω}}{e^{jω}+0.8}\)
2.

An LTI system is characterized by its impulse response h(n)=(1/2)nu(n). What is the spectrum of the output signal when the system is excited by the signal x(n)=(1/4)nu(n)?

A. \(\frac{1}{(1-\frac{1}{2} e^{-jω})(1+\frac{1}{4} e^{-jω})}\)
B. \(\frac{1}{(1-\frac{1}{2} e^{-jω})(1-\frac{1}{4} e^{-jω})}\)
C. \(\frac{1}{(1+\frac{1}{2} e^{-jω})(1-\frac{1}{4} e^{-jω})}\)
D. \(\frac{1}{(1+\frac{1}{2} e^{-jω})(1+\frac{1}{4} e^{-jω})}\)
Answer» C. \(\frac{1}{(1+\frac{1}{2} e^{-jω})(1-\frac{1}{4} e^{-jω})}\)
3.

If an LTI system is described by the difference equation y(n)=ay(n-1)+bx(n), 0

A. \(5+0.888sin(\frac{π}{2}n-420)-1.06cos(πn-\frac{π}{4})\)
B. \(5+0.888sin(\frac{π}{2}n-420)+1.06cos(πn+\frac{π}{4})\)
C. \(5+0.888sin(\frac{π}{2}n-420)-1.06cos(πn+\frac{π}{4})\)
D. \(5+0.888sin(\frac{π}{2}n+420)-1.06cos(πn+\frac{π}{4})\)
Answer» D. \(5+0.888sin(\frac{π}{2}n+420)-1.06cos(πn+\frac{π}{4})\)
4.

If an LTI system is described by the difference equation y(n)=ay(n-1)+bx(n), 0 < a < 1, then what is the parameter ‘b’ so that the maximum value of |H(ω)| is unity?

A. a
B. 1-a
C. 1+a
D. none of the mentioned
Answer» C. 1+a
5.

What is the magnitude of the frequency response of the system described by the difference equation y(n)=ay(n-1)+bx(n), 0

A. \(\frac{|b|}{\sqrt{1+2acosω+a^2}}\)
B. \(\frac{|b|}{1-2acosω+a^2}\)
C. \(\frac{|b|}{1+2acosω+a^2}\)
D. \(\frac{|b|}{\sqrt{1-2acosω+a^2}}\)
Answer» E.
6.

What is the response of the system with impulse response h(n)=(1/2)nu(n) and the input signal x(n)=10-5sinπn/2+20cosπn?

A. 20-\(\frac{10}{\sqrt{5}} sin(π/2n-26.60)+ \frac{40}{3}cosπn\)
B. 20-\(\frac{10}{\sqrt{5}} sin(π/2n-26.60)+ 40cosπn\)
C. 20-\(\frac{10}{\sqrt{5}} sin(π/2n+26.60)+ \frac{40}{3cosπn}\)
D. None of the mentioned
Answer» B. 20-\(\frac{10}{\sqrt{5}} sin(π/2n-26.60)+ 40cosπn\)
7.

What is the magnitude of H(ω) for the three point moving average system whose output is given by y(n)=\(\frac{1}{3}[x(n+1)+x(n)+x(n-1)]\)?

A. \(\frac{1}{3}|1-2cosω|\)
B. \(\frac{1}{3}|1+2cosω|\)
C. |1-2cosω|
D. |1+2cosω|
Answer» C. |1-2cosω|
8.

If h(n) is the real valued impulse response sequence of an LTI system, then what is the phase of H(ω) in terms of HR(ω) and HI(ω)?

A. \(tan^{-1}\frac{H_R (ω)}{H_I (ω)}\)
B. –\(tan^{-1}\frac{H_R (ω)}{H_I (ω)}\)
C. \(tan^{-1}\frac{H_I (ω)}{H_R (ω)}\)
D. –\(tan^{-1}\frac{H_I (ω)}{H_R (ω)}\)
Answer» D. –\(tan^{-1}\frac{H_I (ω)}{H_R (ω)}\)
9.

What is the output sequence of the system with impulse response h(n)=(1/2)nu(n) when the input of the system is the complex exponential sequence x(n)=Aejnπ/2?

A. \(Ae^{j(\frac{nπ}{2}-26.6°)}\)
B. \(\frac{2}{\sqrt{5}} Ae^{j(\frac{nπ}{2}-26.6°)}\)
C. \(\frac{2}{\sqrt{5}} Ae^{j({nπ}{2}+26.6°)}\)
D. \(Ae^{j(\frac{nπ}{2}+26.6°)}\)
Answer» C. \(\frac{2}{\sqrt{5}} Ae^{j({nπ}{2}+26.6°)}\)
10.

If the system gives an output y(n)=H(ω)x(n) with x(n) = Aejωnas input signal, then x(n) is said to be Eigen function of the system.

A. True
B. False
Answer» B. False