tricky Digital Communication Questions & Answers on “Quantization”.
1. Uniform quantizer is also known as
A. Low rise type
B. Mid rise type
C. High rise type
D. None of the mentioned
Answer: B
Clarification: Uniform quantizer is also known as mid rise type quantizer.
2. The SNR value can be increased by _____ the number of levels.
A. Increasing
B. Decreasing
C. Does not depend on
D. None of the mentioned
Answer: A
Clarification: The signal to noise ratio can be increased by increasing the number of levels.
3. Prediction gain _____ for better prediction.
A. Increases
B. Decreases
C. Remains same
D. None of the mentioned
Answer: A
Clarification: Prediction gain increases for better prediction.
4. Delta modulation is
A. 1 bit DPCM
B. 2 bit DPCM
C. 4 bit DPCM
D. None of the mentioned
Answer: A
Clarification: Delta modulation is also considered as 1 bit DPCM.
5. 1 bit quantizer is a
A. Hard limiter
B. Two level comparator
C. Hard limiter & Two level comparator
D. None of the mentioned
Answer: C
Clarification: 1 bit quantizer is also called as two level comparator and also as hard limiter.
6. If step size is increased _____ occurs.
A. Slope overload distortion
B. Granular noise
C. Slope overload distortion & Granular noise
D. None of the mentioned
Answer: B
Clarification: When step size is increased to prevent slope overload distortion, granular noise occurs.
7. Which helps in maintaining the step size?
A. Delta modulation
B. PCM
C. DPCM
D. Adaptive delta modulation
Answer: D
Clarification: Step size if effectively maintained using adaptive delta modulation.
8. The low pass filter at the output end of delta modulator depends on
A. Step size
B. Quantization noise
C. Bandwidth
D. None of the mentioned
Answer: C
Clarification: The design of low pass filter at the output end of delta modulator depends on bandwidth.
9. In early late timing error detection method if the bit is constant, then the slope will be
A. Close to zero
B. Close to infinity
C. Close to origin
D. None of the mentioned
Answer: A
Clarification: In early timing error detection method if the bit is constant and doesn’t change, then the slope will be close to zero.
10. The theoretical gain in zero crossing TED is greater than early late TED.
A. True
B. False
Answer: A
Clarification: The theoretical gain in zero crossing timing error detection is twice more than that in the early late timing error detection method.
11. Non uniform quantizer ______ distortion.
A. Increases
B. Decreases
C. Does not effect
D. None of the mentioned
Answer: B
Clarification: Distortion can be reduced by using non uniform quantizer.
12. Vector quantization is used in
A. Audio coding
B. Video coding
C. Speech coding
D. All of the mentioned
Answer: C
Clarification: Vector quantization is widely used in speech coding for digital cellular systems.
13. The spectral density of white noise is
A. Exponential
B. Uniform
C. Poisson
D. Gaussian
Answer: B
Clarification: The spectral density of white noise is uniform.
14. The probability density function of the envelope of narrow band noise is
A. Uniform
B. Gaussian
C. Rayleigh
D. Rician
Answer: B
Clarification: The probability density function of the envelope of narrow band noise is Gaussian function.
15. The type of noise that interferes much with high frequency transmission is
A. White
B. Flicker
C. Transit time
D. Shot
Answer: C
Clarification: The type of noise that interferes much with high frequency transmission is transit time.
16. Thermal noise power of a resistor depends upon
A. Its resistance value
B. Noise temperature
C. Bandwidth
D. Ambient temperature
Answer: B
Clarification: Thermal noise power of a resistor depends upon noise temperature.