Digital Communication Questions & Answers for freshers on “Uniform and Non Uniform Quantization”.
1. The size of the quantile interval is called as
A. Inter level
B. Step size
C. Quantile size
D. Level width
Answer: B
Clarification: The interval between the quantization levels is called as step size.
2. Uniform quantization provides better quantization for
A. Weak signals
B. Strong signals
C. Weak & Strong signals
D. None of the mentioned
Answer: B
Clarification: Signal to noise ratio is worse for weak level signals.so it provides better quantization for high level signals.
3. Non uniform quantization provides better quantization for
A. Weak signals
B. Coarse signals
C. Weak & Coarse signals
D. None of the mentioned
Answer: A
Clarification: According to signal to noise level ratio non uniform quantization provides better quantization for weak signals.
4. In non uniform quantization, the quantization noise is _______ to signal size.
A. Inversely proportional
B. Directly proportional
C. Equal
D. Double
Answer: B
Clarification: In sampling and quantization, the quantization noise is directly dependent on signal size.
5. The output SNR can be made independent of input signal level by using
A. Uniform quantizer
B. Non uniform quantizer
C. Uniform & Non uniform quantizer
D. None of the mentioned
Answer: B
Clarification: The weak signal experiences poorer SNR compared to high level signals. So if non uniform quantizer like logarithmic compressor is used the SNR ratio can be made independent of input signal level.
6. Companding is the process of
A. Compression
B. Expansion
C. Compression & Expansion
D. None of the mentioned
Answer: C
Clarification: The given signal is first compressed using a logarithmic compressor and then it is given as input to the uniform quantizer. Both these steps together is called as companding.
7. Which value of μ corresponds to linear amplification?
A. μ=0
B. μ=1
C. μ>0
D. μ<0
Answer: A
Clarification: In μ-law compression characteristics, we get linear amplification or uniform quantization when μ=0.
8. What is the standard value of μ in μ-law ?
A. 128
B. 255
C. 256
D. 0
Answer: B
Clarification: The standard value of μ in μ-law is 255.
9. The standard value of A in A-law is
A. 87
B. 88
C. 86.7
D. 87.6
Answer: D
Clarification: Another famous compression characteristic used is A-law. In this law, the standard value of A is 87.6.
10. Which type of quantization is most preferable for audio signals for a human ear?
A. Uniform quantization
B. Non uniform quantization
C. Uniform & Non uniform quantization
D. None of the mentioned
Answer: B
Clarification: The human ear is sensitive to quantization error in small values so non uniform quantization is more preferable than uniform quantization.
Digital Communication for freshers,