Quiz about DSP - Mock Test

Question 1

If x(n) and X(k) are an N-point DFT pair, then X(k+N)=?

Accepted Answer

X(k)

Answer

X(-k)

Answer

-X(k)

Answer

None of the mentioned

Question 2

What is the DFT of the four point sequence x(n)={0,1,2,3}?

Accepted Answer

{6,-2+2j,-2,-2-2j}

Answer

{6,-2+2j-2,-2-2j}

Answer

{6,-2-2j,2,-2+2j}

Answer

{6,-2-2j,-2,-2+2j}

Question 3

Which of the following is true in case of Overlap add method?

Accepted Answer

M-1 zeros are appended at last of each data block

Answer

M zeros are appended at last of each data block

Answer

M zeros are appended at first of each data block

Answer

M-1 zeros are appended at first of each data block

Question 4

Which of the following statements is true?

Accepted Answer

Both DFT and IDFT are periodic.

Answer

Only DFT is periodic and not inverse IDFT.

Answer

Only IDFT is periodic and not inverse DFT.

Answer

Both DFT and IDFT are not periodic.

Question 5

Which of the following is an advantage of fixed-point arithmetic over floating-point arithmetic?

Accepted Answer

Faster computation speed

Answer

Higher precision

Answer

Easier range scaling

Answer

Better handling of overflow and underflow

Question 6

Which arithmetic operation can introduce quantization errors in fixed-point arithmetic?

Accepted Answer

Multiplication

Answer

Addition

Answer

Subtraction

Answer

Division

Question 7

Which representation uses a fixed binary point, where the bit to the right represents the fractional part of the number?

Accepted Answer

Fixed point representation

Answer

Floating point representation

Answer

Sign-magnitude representation

Answer

Two's complement representation

Question 8

The difference between an input value and its quantized value is called:

Accepted Answer

Quantization error

Answer

Overflow error

Answer

Round-off error

Answer

Coefficient error

Question 9

Direct form realization of FIR filters requires ___ registers

Accepted Answer

2M

Answer

M

Answer

M-1

Answer

M+1

Question 10

The values of cutoff frequencies in general depend on which of the following?

Accepted Answer

None of the mentioned

Answer

Type of the window

Answer

Length of the window

Answer

Type & Length of the window

Question 11

Which of the following is the first method proposed for design of FIR filters?

Accepted Answer

Windowing technique

Answer

Chebyshev approximation

Answer

Frequency sampling method

Answer

None of the mentioned

Question 12

Which blocks are not considered the basic building blocks for filter structures?

Accepted Answer

Subtractor

Answer

Adder

Answer

Multiplier

Answer

Delay

Question 13

The different structures for representing FIR Filters are
(i)Cascade Form
(ii)Transposed Form
(iii)Direct Form
(iv)Parallel Form

Accepted Answer

(i) and (iii)

Answer

(i), (ii) and (iii)

Answer

(iii)

Answer

(i) and (iv)

Question 14

What is the order of operations to be performed in order to realize linear phase IIR filter?
 (i) Passing x(-n) through a digital filter H(z)
 (ii) Time reversing the output of H(z)
 (iii) Time reversal of the input signal x(n)
 (iv) Passing the result through H(z)

Accepted Answer

(iii),(i),(ii),(iv)

Answer

(i),(ii),(iii),(iv)

Answer

(ii),(iii),(iv),(i)

Answer

(i),(iii),(iv),(ii)

Question 15

Which of the following filter transformations are not possible?

Accepted Answer

High pass analog filter to high pass digital filter

Answer

High pass analog filter to low pass digital filter

Answer

Low pass analog filter to low pass digital filter

Answer

None of the mentioned

Question 16

What is the equation for normalized frequency?

Accepted Answer

F/Fs

Answer

F.Fs

Answer

Fs/F

Answer

None of the mentioned

Question 17

The magnitude response of an anti-symmetric FIR filter is ______ around the frequency axis.

Accepted Answer

Anti-symmetric

Answer

Symmetric

Answer

Constant

Answer

Random

Question 18

Symmetric FIR filters have an all-zero frequency response at the ______ frequency.

Accepted Answer

Half the sampling rate

Answer

Nyquist

Answer

Zero

Answer

DC

Question 19

If yk(n) is the convolution of the finite duration input sequence x(n) of length N, then what is the impulse response of the filter?

Accepted Answer

WN-kn u(n)

Answer

WN-kn

Answer

WNkn u(n)

Answer

None of the mentioned

Question 20

What is the expression to compute yk(n) recursively?

Accepted Answer

yk(n)=WN-k yk(n+1)+x(n)

Answer

yk(n)=WN-k yk(n-1)+x(n)

Answer

yk(n)=WNk yk(n+1)+x(n)

Answer

None of the mentioned

Question 21

WN^k+N/2=?

Accepted Answer

-WN^k

Answer

WN^k

Answer

WN^-k

Answer

None of the mentioned

Question 22

Consider a 4-point DIF FFT with the input sequence [1, 0, 1, 0]. Calculate the output sequence.

Accepted Answer

[1, 1, 0, 0]

Answer

[1, 0, 1, 0]

Answer

[2, 0, 0, 0]

Answer

[0, 0, 1, 1]

Question 23

For an 8-point DIF FFT, if the output at stage 1 is [2, -1, 4, 3, 0, 0, 0, 0], what is the output sequence at the final stage?

Accepted Answer

[4, -2, 8, 6, 0, 0, 0, 0]

Answer

[2, -1, 4, 3, 0, 0, 0, 0]

Answer

[2, -1, 4, 3, 2, -1, 4, 3]

Answer

[4, -2, 4, 3, 0, 0, 0, 0]

Question 24

Given a 4-point DIF FFT with the input sequence [1, 1, 1, 0], calculate the output sequence.

Accepted Answer

[3, 1 - i, -1, 1 + i]

Answer

[2, 1 - i, 0, 1 + i]

Answer

[1, 2, 3, 4]

Answer

[1, -1, 1, -1]

Question 25

Find 8-point IDFT of a sequence X[k]={4, 1-j2.414, 0, 1-j0.414, 0} using DIF FFT algorithm.

Accepted Answer

{1,1,1,1,0,0,0,0}

Answer

{8,8,8,8,0,0,0,0}

Answer

{8,8,8,8,-8,-8,-8,-8}

Answer

{1,1,1,1,-1,-1,-1,-1}

Question 26

Consider a 4-point DIF IFFT with the input sequence [3, 2, 1, 0]. Calculate the output sequence.

Accepted Answer

[1, 2, 3, 0]

Answer

[0, 1, 2, 3]

Answer

[3, 2, 1, 0]

Answer

[0, 3, 2, 1]

Question 27

For an 8-point DIF IFFT, if the output at stage 1 is [2, -1+j, 3, 1-j, 0, 0, 0, 0], what is the output sequence at the final stage?

Accepted Answer

[4, -1-j, 3, 1, 0, 0, 0, 0]

Answer

[2, -1+j, 3, 1-j, 0, 0, 0, 0]

Answer

[4, -2+2j, 6, -2j, 0, 0, 0, 0]

Answer

[2, -2j, 3, -j, 0, 0, 0, 0]

Question 28

Given a 4-point DIF IFFT with the input sequence [1, j, 0, -j], calculate the output sequence.

Accepted Answer

[0, 1, 0, 0]

Answer

[0, 0, 1, 0]

Answer

[0, 0, 0, 1]

Answer

[1, 0, 0, 0]

Question 29

Find DFT of a sequence x(n)={1,3,2,2,1,3,2,2}using DIF FFT algorithm.

Accepted Answer

{16, 0, -2-2j, 0, -4, 0, -2+2j, 0}

Answer

{16, 0, -2+2j, 0, -4, 0, -2-2j, 0}

Answer

{16, 0, 2-2j, 0, -4, 0, 2+2j, 0}

Answer

{16, 0, 2+2j, 0, 4, 0, 2-2j, 0}

Question 30

Consider a 4-point DIF FFT with the input sequence [1, 2, 3, 4]. Calculate the output sequence.

Accepted Answer

[10, -2+2j, -2, -2-2j]

Answer

[10, -2-2j, -2, -2+2j]

Answer

[1, 2, 3, 4]

Answer

[1+2j, -1, 3, -1-2j]

Question 31

For an 8-point DIF FFT, if the output at stage 1 is [1, -2, 3, 4, 0, 0, 0, 0], what is the output sequence at the final stage?

Accepted Answer

[2, -4, 6, 8, 0, 0, 0, 0]

Answer

[1, -2, 3, 4, 0, 0, 0, 0]

Answer

[1, -2, 3, 4, 1, -2, 3, 4]

Answer

[2, -2, 3, 4, 0, 0, 0, 0]

Question 32

Consider a 4-point DIF FFT with the input sequence [1, 1, -1, 0]. Calculate the output sequence.

Accepted Answer

[1, 1+1j, -2, 1-1j]

Answer

[1, 2j, -2, -2j]

Answer

[1, -1+1j, -2, 1-1j]

Answer

[1, 1+1j, -2, -2j]

Question 33

Which of the following is not an advantage of digital image processing?

Accepted Answer

Higher Bandwidth

Answer

Flexibility

Answer

Accuracy

Answer

Easy Storage

Question 34

What is zero padding technique?

Accepted Answer

Zeroes are added at the end of the sequence to make the number of samples equal to a power of two.

Answer

Zeroes are added at the start of the sequence to make the number of samples equal to a power of two.

Answer

Zeroes are added anywhere in between the sequence to make the number of samples equal to a power of two.

Answer

None of the mentioned.

Question 35

Which of the following statements is invalid about linear convolution?

Accepted Answer

The sequence length of input and output is the same.

Answer

It needs zero padding.

Answer

The input and output sequence is aperiodic.

Answer

All the above statements are valid.

Question 36

In the Overlap add method to compute N point DFT, M-1 zeroes are added

Accepted Answer

At the last of each data block

Answer

At the first of each data block

Answer

In between the data block

Answer

No zeroes are added

Question 37

Which of the following is the disadvantage of Hanning window over rectangularwindow?

Accepted Answer

More width of main lobe

Answer

More side lobes

Answer

Less side lobes

Answer

None of the mentioned

Question 38

Find the dft of the sequence[1,3,1,0]

Accepted Answer

[3, 2-3i, -3, 2+3i]

Answer

[2-3i, 3, 2+3i, 3]

Answer

[3-2i, 3, 3+2i, 3]

Answer

[3, 2+3i, -3, 3-2i]

Question 39

In Overlap save method of long sequence filtering, what is the length of the input sequence block?

Accepted Answer

L+M-1

Answer

L+M+1

Answer

L+M

Answer

None of the mentioned

Question 40

An anti-imaging filter is used

Accepted Answer

after up sampling

Answer

after down sampling

Answer

before up sampling

Answer

before down sampling

Question 41

In interpolation, the sampling rate

Accepted Answer

increases from Fs to LFs

Answer

remains constant

Answer

reduces from Fs to Fs/L

Answer

doubles

Question 42

Why is frequency warping done in digital filter design?

Accepted Answer

To correct for frequency distortion caused by the sampling process

Answer

To adjust the phase response of the filter

Answer

To modify the sampling rate of the filter

Answer

To increase the order of the filter

Question 43

The magnitude response of an IIR filter can be visualized using a:

Accepted Answer

Frequency response plot

Answer

Pole-zero plot

Answer

Phase response plot

Answer

Impulse response plot

DSP - Mock Test

58 questions

If x(n) and X(k) are an N-point DFT pair, then X(k+N)=?

What is the DFT of the four point sequence x(n)={0,1,2,3}?

Which of the following is true in case of Overlap add method?

Which of the following statements is true?

Which of the following is an advantage of fixed-point arithmetic over floating-point arithmetic?

Which arithmetic operation can introduce quantization errors in fixed-point arithmetic?

Which representation uses a fixed binary point, where the bit to the right represents the fractional part of the number?

The difference between an input value and its quantized value is called:

What is the general system function of an FIR system?

The desired frequency response is specified at a set of equally spaced frequencies defined by the equation

Create a free account and access millions of resources

Similar Resources on Wayground

Popular Resources on Wayground

Discover more resources for Science