M.Sc. (Semester III) (CBCS) Examination Oct/Nov-2017
Electronics
DIGITAL SIGNAL PROCESSING
Day Date: Thursday, 16-11-2017 Max. Marks: 70
Time: 02.30 PM to 05.00 PM
Instructions: Attempt five questions.
Q. and are compulsory.
Answer any three questions from Q.3 to Q.7.
Figures to the right indicate full marks.
Q.1 Choose the alternatives given below. 08
The important characteristics of ideal filters are
Ideal filters have constant gain in the passband and zero gain in the
stop band
Ideal filters have zero gain in the passband and constant gain in the
stop band
Ideal filters has nonlinear phase response
Ideal filters have zero gain in the passband and stop band
If is causal sequence then its final value is
0 0
∞ ∞ −
If is anticausal sequence then ROC is .
Interior part of circle of radius
Exterior part of circle of radius
Intersection of two circles of radii
Entire Z plane except 0 ∞
In DIT FET algorithm obtaining N-point DFT numbers of
multiplications are required.
N2 N2 N


2
log2 log2
The advantages of bilinear transformation method are
The mapping is one to one
There is no aliasing effect
There is one to one transformation from the s-domain to z-domain.
All of above
The DFT of delayed unit impulse − is


The necessary condition to use the practical low pass filter without any
distortion is
fs 2w fs 2w
fs 2w fs w
Page 2 of 2
SLR-MJ-360
If is odd then
Imaginary even Imaginary odd
Real odd Real even
State True or false. 06
Using VLSI technology, the hardware of analog filter can be reduced.
If the signal is shifted in frequency, the magnitude spectrum does not
change but only the phase spectrum will be altered.
Convolution of two sequences in the time domain is equivalent to
multiplication of its transforms in Z domain.
Analog filter is stable if the poles lie on the L.H.S. of s-plane.
In Symmetry property of DFT, when x is real valued then

The multiplication of any sequence with gives casual sequence.
Q.2 Attempt any two. 10
Explain how sampling can be done with an impulse function.
Write short note on bilinear transformation.
Obtain the z-transform finite duration sequence
Explain development of fourier transform. 04
Q.3 Given 2n and find using DIT FFT algorithms. 08
Find the 4 point DFT of given window function, 06
Q.4 An analog filter has the following transfer functions using
bilinear.
08
Determine the Z transform and ROC of the given signal
Is the signal is causal?
06
Q.5 State and prove parseval's theorem of DFT. 08
Explain bilinear transformation for IIR filter design. 06
Q.6 Find the Fourier transform of the signal shown in figure. 08
Find Fourier transform and sketch the magnitude spectrum of unit Step
function.
06
Q.7 Using graphical method, obtain a point circular convolution of two DT
signals defined as, and
08
Use residue method to obtain from 06