1. For a given number of bits, the power of quantization noise is proportional to the variance of the signal to be quantized.

A. True

B. False

2. What is the variance of the difference between two successive signal samples, d(n) = x(n) – x(n-1)?

A. \(σ_d^2=2σ_x^2 [1+γ_{xx} (1)]\)

B. \(σ_d^2=2σ_x^2 [1-γ_{xx} (1)]\)

C. \(σ_d^2=4σ_x^2 [1-γ_{xx} (1)]\)

D. \(σ_d^2=3σ_x^2 [1-γ_{xx} (1)]\)

3. What is the variance of the difference between two successive signal samples, d(n) = x(n)–ax(n-1)?

A. \(σ_d^2=2σ_x^2 [1-a^2]\)

B. \(σ_d^2=σ_x^2 [1+a^2]\)

C. \(σ_d^2=σ_x^2 [1-a^2]\)

D. \(σ_d^2=2σ_x^2 [1+a^2]\)

4. If the difference d(n) = x(n)–ax(n-1), then what is the optimum choice for a = ?

A. \({γ_{xx} (1)}{σ_x^2}\)

B. \({γ_{xx} (0)}{σ_x^2}\)

C. \({γ_{xx} (0)}{σ_d^2}\)

D. \({γ_{xx} (1)}{σ_d^2}\)

5. What is the quantity ax(n-1) is called?

A. Second-order predictor of x(n)

B. Zero-order predictor of x(n)

C. First-order predictor of x(n)

D. Third-order predictor of x(n)

6. The differential predictive signal quantizer system is known as?

A. DCPM

B. DMPC

C. DPCM

D. None of the mentioned

7. What is the expansion of DPCM?

A. Differential Pulse Code Modulation

B. Differential Plus Code Modulation

C. Different Pulse Code Modulation

D. None of the mentioned

8. What are the main uses of DPCM?

A. Speech Decoding and Transmission over mobiles

B. Speech Encoding and Transmission over mobiles

C. Speech Decoding and Transmission over telephone channels

D. Speech Encoding and Transmission over telephone channels

9. To reduce the dynamic range of the difference signal d(n) = x(n) – \(\hat{x}(n)\), thus a predictor of order p has the form?

A. \(\hat{x}(n)=\sum_{k=1}^pa_k x(n+k)\)

B. \(\hat{x}(n)=\sum_{k=1}^pa_k x(n-k)\)

C. \(\hat{x}(n)=\sum_{k=0}^pa_k x(n+k)\)

D. \(\hat{x}(n)=\sum_{k=0}^pa_k x(n-k)\)

10. The simplest form of differential predictive quantization is called?

A. AM

B. BM

C. DM

D. None of the mentioned

11. What is the abbreviation of DM?

A. Diameter Modulation

B. Distance Modulation

C. Delta Modulation

D. None of the mentioned

12. In DM, the quantizer is a simple ________ bit and ______ level quantizer.

A. 2-bit, one-level

B. 1-bit, two-level

C. 2-bit, two-level

D. 1-bit, one level

13. In DM, What is the order of predictors is used?

A. Zero-order predictor

B. Second-order predictor

C. First-order predictor

D. Third-order predictor

14. In the equation xq(n)=axq(n-1)+dq(n), if a = 1 then integrator is called?

A. Leaky integrator

B. Ideal integrator

C. Ideal accumulator

D. Both Ideal integrator & accumulator

15. In the equation xq(n)=axq(n-1)+dq(n), if a < 1 then integrator is called?

A. Leaky integrator

B. Ideal integrator

C. Ideal accumulator

D. Both Ideal integrator & accumulator

16. What is the main function of (A/D. or ADC converter?

A. Converts Digital to Analog Signal

B. Converts Analog to Digital signal

C. All of the mentioned

D. None of the mentioned

17. What is the main function of (D/A. or DAC converter?

A. Converts Digital to Analog Signal

B. Converts Analog to Digital signal

C. All of the mentioned

D. None of the mentioned

18. The S/H is a digitally controlled analog circuit that tracks the analog input signal during the sample mode and then holds it fixed during the hold mode to the instantaneous value of the signal at the time the system is switched from the sample to the hold mode.

A. True

B. False

19. The time required to complete the conversion of Analog to Digital is ________ the duration of the hold mode of S/H.

A. Greater than

B. Equals to

C. Less than

D. Greater than or Equals to

20. In the A/D converter, what is the time relation between sampling period T and the duration of the sample mode and the hold mode?

A. Should be larger than the duration of sample mode and hold mode

B. Should be smaller than the duration of sample mode and hold mode

C. Should be equal to the duration of sample mode and hold mode

D. Should be larger than or equal to the duration of sample mode and hold mode

21. In the practical A/D converters, what are the distortions and time-related degradations that occur during the conversion process?

A. Jitter errors

B. Droops

C. Nonlinear variations in the duration of the sampling aperture

D. All of the mentioned

22. In the absence of an S/H, the input signal must change by more than one-half of the quantization step during the conversion, which may be an impractical constraint.

A. True

B. False

23. The noise power σn2 can be reduced by increasing the sampling rate to spread the quantization noise power over a larger frequency band (-Fs/2, Fs/2).

A. True

B. False

24. What is the process of down-sampling called?

A. Decimation

B. Fornication

C. Both Decimation & Fornication

D. None of the mentioned

25. If the interpolation factor is I = 256, the A/D converter output can be obtained by averaging successive non-overlapping blocks of 128 bits.

A. True

B. False