UNIT-I. 2. A real valued sequence x(n) is anti symmetric if a) X(n)=x(-n) b) X(n)=-x(-n) c) A) and b) d) None Ans: b)

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1 DIGITAL SIGNAL PROCESSING UNIT-I 1. The uit ramp sequece is Eergy sigal b) Power sigal c) Either Eergy or Power sigal d) Neither a Power sigal or a eergy sigal As: d) 2. A real valued sequece x() is ati symmetric if X()=x(-) b) X()=-x(-) c) A) ad b) d) Noe As: b) 3. The discrete time system described by y 2 ( ) x( ) Causal, liear ad time varyig b) Causal, o liear ad time varyig c) No Causal, liear ad time varyig d) No Causal, No liear ad time varyig As: c) 4. Fid the rage of a for which the LTI system with impulse respose h( ) a u( ) is stable a 1 b) a 1 c) a 0 d) Noe As: 5. The process of computig the covolutio ivolves Foldig b) Shiftig c) Multiplicatio ad Summatio d) All the above As: d) 6. The Fourier trasform of ( ) is 1/ j b) 1 is

2 c) j d) j / As: b) 7. The umber of elemets i the covolved sequece of x() havig N elemets ad h() havig M elemets is M+N b) N+M+1 c) N+M-1 d) N-M As: c) 8. Determie the covolutio of x( ) a u( ) ad h( ) b u( ) 1 1 b a / b a 1 1 b) b a / b a c) a / b a d) Noe As: b) 9. Compute the uit step respose of a LTI System whose impulse respose is h( ) c u( ) 1 1 c / 1 c 1 b) 1 c / 1 c 1 c) 1 c / 1 c 1 d) 1 c / 1 c As: 10. Fid the covolutio of x()={1,1,1,1,} with h()={2,2,2,2} {2,4,6,8,6,4,2} b) {2,4,6,8,6,4,4} c) {2,4,6,6,8,4,2} d) {2,4,6,8,6,2,2} As: 11. The discrete time system described by y( ) cos[ x( )] is Ustable b) Stable c) Dyamic

3 d) Nocausal As: 12. Express the impulse sequece i terms of uit step sequece ( ) u( ) u( 1) b) ( ) u( ) u( 1) c) ( ) u( ) u( 2) d) ( ) u( ) u( 1) As: d) j 13. The sufficiet coditio for covergece of Xe ( ) x ( ) b) x ( ) c) x ( ) is absolutely summable d) Noe As: c) 14. The Fourier Trasform of u() j 1 1 e j b) 1 1 e j c) 1 1 e j d) 1 1 e As: is 15. Fid the fourier trasform of ( 100) b) c) d) e e j10 j100 j10 e j100 e As: b) jw0 16. F[ e x( )] = b) X e j w w 0 X e j w w 0

4 jw c) Xe 0 d) Noe As: b) 17. F[ x( )* y( )] = X ( w) / Y( w ) b) X ( w) Y( w ) c) X ( w) Y( w) d) X ( w) Y( w) As: b) 18. F. x( ) jw d X ( e ) / b) jw jd X ( e ) / c) jw d X ( e ) / d) jd X e jw dw dw dw ( ) / dw As: b) 19. The Uit step sequece is Eergy sigal b) Power sigal c) Either Eergy or Power sigal d) Neither a power sigal or eergy sigal As: b) 20. Fid the power of the sigal A b) A / 2 c) A 2 jw Ae d) 2A As: c) UNIT-II 21. Express the N-poit DFT i Matrix form X W X N N N b) X W X * N N N

5 c) ad b) d) Noe As: 22. Express the N-poit IDFT i Matrix form X W X N N N b) * c) X X 1/ N W X N N N W X * N N N d) Noe As: b) 23. Fid the 4-pt DFT of {1,1,1,1} b) {1,1,0,0} c) {0,0,1,1} d) {1,0,0,0} As: 24. Fid the 4-pt DFT of 2 {1,1,1,1} b) {1,-1,1,-1} c) {1,-1,1,1} d) {-1,1,-1,1} As: b) 25. Fid the 4-pt DFT of 1 u() {0,0,0,4} b) {0,4,0,0} c) {1,1,1,1} d) {0,0,4,0} As: d) 26. Differetiate betwee DFT ad DFS of sequece Both periodic b) Both o periodic c) No periodic ad periodic d) All the above As: c) 27. Periodicity property of N-pt DFT is x( N) x() b) X(K N) X(K) c) ad b) d) oe As: c)

6 28. X(K) = X(N K) b) X(N K) c) X( K) d) b) ad c) As: d) 29. Fid the liear covolutio of x1 ={ } ad 2 x = { } {1,3,6,10,9,7,4} b) {1,3,6,10,9,7,1} c) {3,3,6,10,9,7,1} d) {1,3,6,10,9,7,7} As: 30. Fid the IDFT of X(K)=1 for N=4 {1,1,1,1} b) {1,0,0,0} c) {0,0,0,1} d) {1,1,0,0} As: b) 31. X K R XR N K b) X N K R c) ad b) d) oe As: b) 32. XI K = XI N K b) XI N K c) X N K I d) b) ad c) As: c) 33. Fid circular covolutio of {1,1,1,1,} ad {2,2,2,2} {8,8,8,8} b) {8,0,0,0} c) {0,0,0,8} d) {0,0,8,0} As:

7 34. 2K W N = b) c) d) 4K W N K W N2 2K W N2 K W 2N As: b) 35. The umber of complex multiplicatios required i DIFFFT algorithm is Nlog2 N b) N / 2log 2 N c) 2Nlog 2 N d) Nlog 2 2N As: b) 36. The umber of complex multiplicatios required i N-Pt DFT algorithm is 2 N b) 2N c) N/2 d) N-1 As: 37. The umber of complex additios required i N-Pt DFT algorithm is N(N+1) b) N(N-1) c) (N-1)(N-2) d) (N+1)(N-1) As: b) 38. Arg[X(K)]= Arg[X(N+K)] b) Arg[X(N-K)] c) -Arg[X(N-K)] d) b) ad c) As: c) 39. The umber of complex additios ad multiplicatios required i 16-Pt DFT 250, 250 b) 256, 250 c) 256, 240 d) 253, 243 As: c)

8 40. The Bit Reversal Order for a 8-poit FFT is 0,1,2,3,4,5,6,7 b) 0,4,2,6,1,5,3,7 c) 4,5,6,7,0,1,2,3 d) 3,2,1,0,7,6,5,4 As: b) 41. Z () = UNIT-III 1/z b) z c) 1 d) -1/z As: c) Z 1 u(n) z/(z+1) b) z/(z-1) c) 1/(z+1) d) 1/(z-1) As: Zx(2) = a. X(2z) b. X z c. X(z / 2) d. X(z) As: b) 44. if the x x / k,for / k is a itger k k = 0, otherwise X z = k Xz

9 b) Xkz c) Xz / k d) Xk / z As: 45. fid the G(z) i terms of F(z) if g()= b) 1 G(z) F(z) / (1 z ) 1 G(z) F(z) / (1 z ) c) G(z) F(z) / (1 z) k0 f (k) u() d) G(z) F(z) / (1 z) As: 46. The miimum umber of delay elemets required i realizig a digital filter with the 1 2 1az bz trasfer fuctio H(z) cz dz dz 2 b) 3 c) 4 d) 5 As: b) 47. Fid the iverse z-trasform of 2 a u() b) c) d) 1 a u() a u() a 1 u() z / z a As: b) 48. Fid the ROC of a u 1 z a b) z a c) z a d) z a As: b) 49. The z-trasform of A x() is X(Az) b) X(A/z) c) X(z/A) d) Noe As: c)

10 50. Fid the ROC of a sequece 100 All values of z except z=0 b) All values of z except z= c) ad b) d) Noe As: 51. Fid the ROC of z a b) z a c) z a a cos(w)u() d) z a As: 52. Fid the ROC of {1,2,3,4,5} all values of z except z=0 b) all values of z except z= c) ad b) d) Noe As: c) 53. The system fuctio of a LTI system described by the differece equatio y() 5y( 1) 6y( 2) 2x( 1) 1 2z H(z) 1 5z 6z z b) H(z) z 6z c) ad b) d) Noe As: a 54. The stability coditioof a LTI system i z-plae is ROC of sysem fuctio excludes the uit circle b) ROC of sysem fuctio icludes the uit circle c) Etire z plae except z=0 ad z= d) Uit circle As: b)

11 The system fuctio H(z) 1/ 1 1 2z 1 1 4z is Ustable b) Stable c) Udefied d) Noe As: b) 56. Digital filter realizatio techiques are Direct b) Caoic c) Cascade d) All of the above As: d) jw 57. The iverse Fourier trasform of 1 2 u() b) 1/ 2 u() c) d) 1 2 u() 1 2 u( 1) X(w) 1 1/ 2e As: b) UNIT-IV 58. The filter desiged by cosiderig all the ifiite samples of impulse respose is called Ifiite impulse filter b) Fiite impulse filter c) Impulse Ivariat trasformatio d) Biliear trasformatio As: 59. The two techiques used to trasform aalog filter to digital filter are Chebyshev, butterworth b)biliear, impulse ivariat c) IIR, FIR d) Noe As: b) 60. The tolerace i the pass bad ad stop bad are called Stable pulses b) causal delays c) ivariat delays d) ripples As: d) 61. I impulse ivariat mappig the poles of s-plae are mapped ito of uit circle i z-plae

12 Left half, iterior b) Right half, exterior c) Left half, exterior d) Right half, iterior As: 62. The pheomea of high frequecy compoets acquirig the idetity of low frequec compoets is called Samplig b) aliasig c) Wrapig d) Noe As: b) 63. The Impulse Ivariat mappig is mappig may-to-oe c) oe-to-may b) oe-to-oe d) may-to-may As: 64. The distorto i frequecy axis due to oliear relatioship betwee aalog ad digital frequecy is called Aliasig c) frequecy wrappig b) Prewrappig d) Noe As: c) 65. At the cut-off frequecy, the magitude of the butterworth filter is times the maximum value 2 b) 1/ 2 c) 3 d) 1/ 3 As: b) 66. I type-i chebyshev approximatio the magitude respose is i the Pass bad ad is i the stop bad equiripple, mootoic c) mootoic, equiripple b) mootoic, mootoic d) Noe 67. The type-2 magitude respose is called respose Iverse butterworth c) iverse chebyshev b) Butterworth d) Noe As: c) 68. The poles of Chebyshev trasfer fuctio symmetrically lies o i s-plae Circle b) parabola c) Ellipse d) Noe As: b) 69. The relatio betwee aalog ad digital frequecies i impulse ivariat trasformatio is 2 2 /T b) T c) T d) Noe As: c) 70. The Biliear mappig is accomplished whe 1 z s 2 / T 1 z z s T / 2 1 z b) 1 1 c) 1 z s 2T 1 z 1 1 d) Noe As:

13 71. I Biliear Trasformatio the digital frequecy is give by ta T / 2 b) 2cot T / 2 c) ta T / 2 1 d) ta T As: UNIT-V 72. DTMF stads for Dual Toe Multi Frequecy b) Discrete Trasform Mai Frequecy c) Double Time Multiple Format d) Noe As: 73. The Frequecy, f k i Hz correspodig to the DFT idex, k is give by where F T is samplig frequecy fk kf T / N b) fk knft c) NF T / k d) Noe As: 74. STFT stads for Short Time Fourier Trasform b) Sequetial Timig i Frequecy Toes c) Short Trouble Fial Toe d) Noe As: 75. Idetify the Ideal Hilbert Trasformer jw j, 0 to jw 1, 0 to H(e ) b) H(e ) j, to 0 1, to 0 c) jw 1, 0 to jw j, 0 to H(e ) d) H(e ) 0, to 0 0, to 0 As: 76. I Voice Privacy system, TFSP stads for Toe Frequecies Sequetial Primitives b) To ad Fro Soud Privacy c) Time ad Frequecy Segmet Permutatio d) Noe As: c)

14 77. A applicatio of DSP i FDM, sub carriers are chose to esure that the spectra of the modulated sigal do ot overlap to avoid Cross talk b) Cross modulatio c) Aliasig d) Noise or Distortio As: 78. QMF stads for Quatizig Multiple Frequecy b) Quality measuremet factor c) Quadrature Mirror Filter d) Noe As: c) 79. Filters desiged by selectig fiite umber of samples of impulse respose are called Fiite Impulse Respose Filters b) Ifiite Impulse Respose Filters c) Impulse Ivariat Trasformatio d) Noe As: 80. The coditios to be satisfied for costat phase delay i liear phase FIR filters are N 1 / 2, h() h(n 1 ) b) 2 N 1, h() h N 1 / 2 c) N 1/ 2, h() hn 1/ 2 d) Noe As: Choose Hd ; 2. Fid hd from Hd T ; 3. Trucate hd to h 4. Take Z-trasform of h for H(z); Idetify the Desig techique suitable for the above steps Frequecy samplig Method b) Widow Method c) Fourier Series Mehod d) Optimal Filter Desig Method As: c) 82. The abrupt trucatio of impulse respose itroduces oscillatios i the pass bad ad stop bad. This effect is kow as Kaiser Oscilatios b) Aliasig c) Gibb s Pheomeo d) Noe As: c) 83. I Rectagle Widow, the mai lobe width is equal to 4 / N b) 2 / N c)8 / N d) 16 / N As: 84. I Rectagle Widow, Maximum side lobe magitude is equal to -3 db b) -13 db c) -23 db d) Noe As: b)

15 85. I triagular widow, the mai lobe width is equal to 4 / N b) 8 / N c) 2 / N d) 16 / N As: b) 86. I triagular widoe, the maximm side lobe magitude is equal to -5 db b) -15 db c) -25 db d) -35 db As: c) 87. I Hammig widow, the maximum side lobe magitude is equal to -4 db b) -4.1 db c) -31 db d) Noe As: b) 88. I Haig widow, the maximum side lobe magitude is -3 db b) -13 db c) -41 db d) -31 db As: d) 89. I Blackma widow, the mai lobe width is 2 / N b) 8 / N c) 4 / N d) 12 / N As: d) 90. I Blackma widow, maximum side lobe magitude is -8 db b) -31 db c) -41 db d) -58 db As: d) 91. The frequecy respose of digial filter is periodic with period equal to Samplig frequecy b) cut-off frequecy c) Phase delay d) group delay As: 92. Oscillatios ca be reduced by multiplyig the impulse respose by a appropriatewidow fuctio Gibb s b) Laplace s c) siusoidal d) Noe As: 93. Ideal filters are causal b) No- causal c) stable d) Ustable As: b) 94. The phase distortio is due to characteristics of the filter No liear phase b) Liear phase c) curviliear phase d) Mootoic As: 95. I Blackma widow spectrum, the width of mai lobe is that of Rectagular widow for some value of N Same as b) double c) ripple d) four times As: c) 96. The vocal tract has certai ormal resoat modes of vibratio called as Articulators b) Formats c) glottis Vibrators d) Noe As: b)

16 97. The term homomorphic processig is applied to a class of systems that obey a geeralized priciple of superpositio b) Time Ivariat c) Liearity d) Causality As: 98. Appedig zeros to a sequece i order to icrease is legth is called Overlappig zeros b) overflowig zeros c) Paddig zeros d) Noe As: c) 99. I magitude respose of the DFT of a sigal, the bi crossover the result i a sigal loss at frequecy poits off the DFT bi ceters. This is referred to as Scallopig Loss b) Picket-fece effect C) ad b) d) Noe As: c) 100. The Z-Trasform of * * * X z b) * x () is X z c) * X z d) Noe As :

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