# Digital Signal Processing MCQ (Multiple Choice Questions)

Q1.If x(n) and X(k) are an N-point DFT pair, then X(k+N)=?

• X(-k)
• -X(k)
• X(k)
• -X(-k)

Ans:- C : X(k)

Q2. DFT is applied to

• Infinite sequences
• Finite discrete sequences
• Continuous infinite signals
• Continuous finite sequences

Ans:- Finite discrete sequences

Q3. The Elliptic filters have

• Flat pass band and Equiripple stop band
• Flat stop band and Equiripple pass band
• Flat stop band and Flat pass band
• Equiripple pass band and Equiripple stop band

Ans:- Equiripple passband and Equiripple stopband

Q4. In Digital Active cross Preamplifier is used after

• Source
• Digital Active crossover
• Amplification
• Output

Ans:- Source

Q5. An analog LTI system with system function H(s) is stable

• If all its poles lie in the left half of the S Plane
• If all its zeros lie in the right half of the S Plane
• If all its poles lie in the right half of the S Plane
• If all its zeros lie in the left half of the S Plane

Ans:- If all its poles lie in the left half of the S Plane

Q6. Role of the Anti-aliasing filter is to remove

• low frequency
• high frequency
• medium frequency
• All frequency

Ans:- high frequency

Q7. Impulse Response of an IIR filter is

• Finite duration
• Infinite duration
• Limited to the fundamental period
• Equal to system function

Ans:- Infinite duration

Q8. A vocoder consists of

• Only Encoder
• Only decoder
• Both encoder and decoder
• Encrypt and Decrypt

Ans:- Both encoder and decoder

Q9. In Overlap add method, what is the length of each input data block?

• L-1
• L
• L+1
• L+2

Ans:- L

Q10.The circular convolution of two sequences in time domain is
equivalent to

• Multiplication of DFTs of two sequences
• Summation of DFTs of two sequences
• Difference of DFTs of two sequences
• Square of multiplication of DFTs of two sequences

Ans:- Multiplication of DFTs of two sequences

Q11. The IIR Filter designing process involves

• Designing of digital filter in analog domain and tranforming into digital domain
• Designing of digital filter in digital domain and tranforming into analog domain
• Designing of analog filter in analog domain and tranforming into digital domain
• Designing the Digital filter directly with no conversions

Ans:- Designing of digital filter in analog domain and tranforming into digital domain

Q12. Which of the following is true in case of Overlap add method?

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

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

Q13. Consider the assertions given below. Which among them is an advantage of FIR Filter?

• Necessity of computational techniques for filter implementation
• Presence of linear phase response
• Requirement of large storage
• Incapability of simulating prototype analog filters

Ans:- Presence of linear phase response

Q14. If all the poles of H(z) are outside the unit circle, then the system is said to be

• Only causal
• Only BIBO stable
• BIBO stable and causal
• BIBO Unstable

Ans:- BIBO Unstable

Q15. Which frequency is calculated in Vibration Analysis for Defective Gear Teeth

• Low frequency
• Meshing Frequency
• High Frequency
• Medium frequency

Ans:- Meshing Frequency

Q16. Volume control can be done digitally at

• Source
• Digital cross over
• Source and Digital cross over
• Speaker

Ans:- Digital cross over

Q17. Which one of the structures is NOT used for realisation of a digital IIR filter?

• Direct Form 1&2
• Lattice Form
• Parallel Form

Ans:- Lattice Form

Q18. ECG signal is corrupted with

• Channel Noise
• Contact Noise
• Channel Noise and Contact Noise
• Interference Noise

Ans:- Channel Noise and Contact Noise

Q19. Power line interference in ECG introduces frequency components of

• 50 Hz to 60Hz
• 60Hz to 70Hz
• 10 Hz to 20Hz
• 20Hz to 40Hz

Ans:- 50 Hz to 60Hz

Q20. Frequency Discriminator in Voice encoders are used before

• LPF
• HPF
• DAC

Q21. If all the poles of H(z) are inside the unit circle, then the system is said to be

• Only causal
• BIBO stable and causal
• BIBO causal
• Only BIBO stable

Ans:- BIBO stable and causal

Power Electronics MCQs 1