PARISUTHAM INSTITUE OF TECHNOLOGY & SCIENCE
DEPARTMENT OF ECE
AY-2015 -2016
III Year / V Sem.
TECHNICAL QUIZ-1
Sub Code/Name: EC6502/Principles of digital Signal Processing
Topic: Unit 1 & Unit 3
1) What is the condition to perform circular
convolution of two sequences?
a) length must be equal
b) length of one must be greater
c) length of one must be smaller
d) both b and c
2. The DFT of a signal x(n) of length N is
X(k). When X (k) is given and x (n) is
computed from it, What is the length of x(n) ?
a)is increased to infinity
b) remains N
c) becomes 2N – 1
d) becomes N
3. What is the length of output sequence for
linear convolution if L=3 and M=5?
a) 5
b) 6
c) 7
d) 8
4. What is the length of output sequence for
circular convolution if L=3 and M=5?
a)5
b) 6
c) 7
d) 8
5. Which signals can have only a limited
number of values?
a) Analog
b) Digital
c) (a)or (b)
d) None of the above
6. How many adders are required to realize a
32 point DFT?
a) 992
b) 1024
c) 4096
d) 2048
7. How many multiplications are required to
realize a 32 point DFT?
a) 992
b) 1024
c) 4096
d) 2048
8. What is the conversion of CT signals into a
DT signals ?
a) Sampling
b) Quantization
c) Coder
d) ADC
9. What is the conversion of DT signals into a
discrete value signals?
a) Sampling
b) Quantization
c) Coder
d) ADC
10. For DIT-FFT, the input must be in which
order?
a) Normal order
b) Bit reverse order
c) Reverse order d) Complement form
11. How many of stages in 64-point FFT ?
a)3
b)4
c)5
d)6
12. How many number of stages in 512-point
FFT?
a) 5
b) 7
c) 9
d) 11
13. What is the need of Convolution?
a)The impulse response of an LTI
System
b) Frequency response of a System
c) The time response of a LTI system
d)The phase response of a LTI system
14. WN
a) e
nK
is
 j 2 K
N
c) e  j 2nK
b) e
d) e
 j 2
N
2  Kn
N
15. When the sequence is circularly shifted in
time domain by ‘m’ samples i.e. x((n-m))N
then on applying DFT, what it is equivalent
multiply sequence in frequency domain ?
a) e
j 2  Km
N
b) e
 j 2  Km
c) e
d) e
 j 2  Km
N
2 Km
N
16. What is the result of Multiplication of
sequence in time domain, on apply DFT, it
corresponds to circular convolution in
frequency domain ?
 X1(K)*X2(K)
a) x1(n) x2(n) 
DFT
 X1(K)X2(K)
b) x1(n) x2(n) 
DFT
 X1(K)
c) x1(n) * x2(n) 
DFT
X2(K)
N 1

 K  0 X1(K)X2(K)
d) x1(n) x2(n) 
17. What is the length of an output sequence
for linear convolution of two sequences N1
and N2?
a) N1 – N2 +1
b) N1 + N2 –1
c) N1 + N2 +1
d) 2N1 – N2 +1
18. What is the number of sets or sections of
butterflies in each stage?
a) 2N
b) n log n
c) log n
d) n/2 log n
DFT
19. How many number of complex
multiplications are required to calculate
Radix-2 FFT?
a) 2N
b) n log n
c) log n
d) n/2 log n
20. What is zero padding?
a) Appending zeros to a sequence
b) decreasing zeros to a sequence
c) adding ones to a sequence
d) subtracting zeros
21. What is the Conversion of a continuous
time signal into a digital value produces?
a)
Input
quantization
error
b) output quantization error
c) co-efficient quantization error
d) product quantization error
22. What is the p(e) for two’s complement
truncation ?
a) q
b) 1-q
c) 1/q
d) q/2
23. What is the two’s complement of negative
number when all the bits of the positive
number and adding one ?
a)Adding, MSB
b) complementing ,least significant bit
c) subtracting, MSB
d) all the above
24. What are the Common methods of
quantization?
a) Rounding
b) truncation
c) aliasing
d) both a & b
25. From the assumptions of the effects of
rounding in digital filter error sequence, what
type of signal e(n) is ?
a) Thermal noise
b) shot noise
c) white noise
d) Attenuation
26. How many quantization errors in finite
word length register?
a) 1
b) 2
c) 3
d) 4
27. What realization is less sensitive to
process of quantization?
a) Cascade
b) Parallel form
c) Direct form-1 d) Direct form-2
28. What are the methods used to prevent
over flow?
a) Limit cycle, saturation arithmetic
b) overflow limit cycle, saturation arithmetic
c) saturation arithmetic; signal scaling
d) none of the above
29. What is A/D converter output?
a) x(n)+ e(n) b) x(n)- e(n)
c) e(n)
d) x(n)
30. In one’s compliment representation, what is
the error for truncation of positive values of the
mantissa?
a) 0>=mt-m>-2^b
b) 0>=mt >-2^b
c) 0>= m>-2^b
d) mt-m>-2^b
31. What is the application of DFT in DSP ?
a) Spectral analysis b) digital filtering
c) both a & b
d) none of the above
32. What is the Finite precision representation
of number in a digital system ?
a) Finite word length b) Register word length
c )Floating point
d) Fixed point
33. When the quantization and coding will
introduce, what is the name of the error in input
data?
a) Error due to quantization of filter coefficient
b) Error due to quantization of input data
c) Error due to quantization of input data by
ADC
d) Limit cycles
34. How many quantization levels in 8-bit
register word length?
a) 128
b) 256
c) 512
d) 64
35. What operation leads to truncation and
rounding error in floating point representation?
a) Multiplication
b) Addition
c) Multiplication and addition d) Subtraction
36. What operation leads to truncation and
rounding error in fixed point representation?
a) Multiplication
b) Addition
c) Multiplication and addition d) Subtraction
37. In which of the following, Overflow is rare?
a) Mantissa
b) Exponent
c) Fixed point
d) Floating point
38. What is the process of reducing size of
binary number by discarding all bits less
significant?
a) Rounding
b) Truncation
c) Quantization
d) None
39. When a stable IIR digital filter is excited by a
finite input sequence what is the output will
ideally decay?
a) 0
b) 1
c) 2
d) 3
40. What is the process of rounding?
a) Truncation and addition
b) Discarding and addition
c) Truncation and subtraction
d) Truncation
41. What is the Error due to representation of
sampled signal by a fixed number of digital
levels?
a) Saturation error
b) Quantization error
c) Step size error
d) Truncation error
42. What is the Error occurs when analog signal
exceed the range of ADC?
a) Saturation error
b) Quantization error
c) Step size error
d) Truncation error
43. What is the Quantization step size for 2’s
complement?
a)
𝑅
2𝑏
−1
b)𝑅/(2𝑏 − 1)
c) 𝑅/2𝑏
d)𝑅/2𝑏−1
44. What is the Steady state input noise power?
a) 𝑞 2 /24
b) 𝑞 2 /15
2
c) 𝑞 /2
d) 𝑞 2 /12
45. What is the error due to quantization in
multiplication ?
a) Error due to quantization of filter coefficient
b) Error due to quantization of input data
c) Error due to quantization of input data by
ADC
d) Limit cycles
46. What is the amplitude of the outputs during
limit cycles are confined to range of values calle
a) Pass band
b) Stop band
c) Dead band
d) None
47.What is the nature of IIR digital filter?
a)Recursive
b) Non Recursive
c)Reversive
d)Non Reversive
48. Number of complex additions required to
calculate Radix – 2 FFT is
a) 𝑁 − 1
b)
𝑁
2
𝑙𝑜𝑔2 𝑁
c) 𝑁𝑙𝑜𝑔2 𝑁
d) 𝑁
49. What type of signals can have only a limited
number of values?
a)Analog
b)Digital
c)(a) or (b)
d)Discrete
50. Which of the following is having more
computation?
a)DIT
b) DIF
c) a and b
d) DFT
Faculty Signature:
Faculty Name: B. Kruthika
References:
1.http://dspguru.com/book/export/html/8
2. http://iitg.vlab.co.in/
3. http://www.indiabix.com/
HOD Signature