**Pulse Code Modulation:**

- What is PCM? Does PCM come under Digital Modulation technique?
- What are the applications of PCM?
- What is the need for Regenerative repeaters in PCM?
- Draw the block diagram of PCM system.
- Define µ-law and A-law. And draw the characteristics of two laws.
- What is meant by Quantization?
- Differentiate Uniform and Non uniform Quantization techniques.
- What is meant by companding in PCM?
- What are the advantages and disadvantages of PCM?
- What is the difference between ADC & PCM?
- Name some ADC circuits?
- Which ADC is fastest ADC circuit?
- What is slope overload distortion?
- Draw the waveforms of PCM modulation and demodulation.
- State sampling theorem.
- What is aliasing?
- Give the expression for aliasing error and the bound for aliasing error.
- What is quantization?
- What are the various steps involved in A/D conversion.
- Define step size.
- What is the importance of regenerative repeater?
- List out the three basic functions of regenerative repeater.
- What is companding?
- Write the mean square quantization error if the step size is S.
- What is a mid tread Quantizer?
- What is a mid rise Quantizer?
- What do you mean by quantizing process?
- What will happen when sampling rate is greater than Nyquist rate?
- What will happen when sampling rate is less than Nyquist rate?
- Find the A/D Converter output for input DC voltage of 3.6V.
- In digital telephony, (a) what kind of modulation is used? (b)Give the typical sampling rate, output data rate and speech signal Bandwidth.
- Mention some applications of PCM.
- What is the function of Sample and Hold circuit?
- Write the expression for SNR in decibels of a PCM system.
- For a DAC the required resolution is 25mv and the total input is 5V. the number of bits required would be——————————————.

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