EC2252 Communication Theory Question Bank : kings.ac.in

Name of the College : Kings College Of Engineering
Department : Electronics & Communication Engineering
Subject : Communication Theory
Website : kings.ac.in
Document Type : Question Bank

Download Model/Sample Question Paper : https://www.pdfquestion.in/uploads/ki…N%20THEORY.pdf

Kings Communication Theory Question Paper

Unit I

Amplitude Modulation Systems :
Part-A : (2 Marks)
1. Define Amplitude Modulation.
2. What is AM wave envelope?
3. Define modulation index for an AM wave.

Related : MG1351 Principles of Management B.E Question Bank : www.pdfquestion.in/1466.html

4. List out the advantages of AM.
5. Define the transmission efficiency of AM signal
6. As related to AM, what is over modulation, under modulation and 100% modulation?
7. Define FDM .
8. Define SSB.
9. Mention the applications of SSB.
10. Mention the advantages of VSB.

Part-B : (16 Marks)
1. (a).Explain the generation of AM signals using square law modulator. (8)
(b).Explain the detection of AM signals using envelope detector. (8)
2. Explain Balanced modulator to generate DSB-SC signal. (16)
3. Explain coherent detector to detect SSB-SC signal. (16)
4. Explain the generation of SSB using balanced modulator. (16)
5. Draw the circuit diagram of Ring modulator and explain with its operation. (16)
6. Discuss the coherent detection of DSB-SC modulated wave with a block diagram
of detector and Explain. (16)
7. Draw the block diagram for the generation and demodulation of a VSB signal and explain the principle of operation. (16)
8. Write short notes on frequency translation and FDM. (16)

Unit II

Angle Modulation Systems :
Part-A :(2 Marks)
1. Define PM.
2. Define FM.
3. Define Frequency deviation(f)
4. Define Carson’s rule.
5. Write the applications of FM
6. What do you mean by narrowband and wideband FM?
7. What is modulation index of PM?
8. Define Direct method and Indirect method FM.
9. Mention the advantages of FM.
10. What is the modulation index of FM?

Part-B : (16 Marks)
1. Explain the indirect method of generation of FM wave and any one method of demodulating an FM wave. (16)
2. Derive the expression for the frequency modulated signal. Explain what is meant by narrowband FM and wideband FM using the expression? (16)
3. Explain any two techniques of demodulation of FM. (16)
4. Explain the working of reactance tube modulator and derive an expression to show how the variation of the amplitude of the input signal changes the frequency of the output signal of the modulator. (16)
5. Draw the frequency spectrum of FM and explain. Explain how Varactor diode can be used for frequency modulation. (16)
6. Discuss the indirect method of generating a wide-band FM signal. (16)
7. Draw the circuit diagram of Foster-Seelay discriminator and explain its working. (16)

Unit III

Noise Theory :
Part-A :(2 Marks)
1. Define internal noise.
2. Define shot noise.
3. Define thermal noise.
4. Define narrow band noise.
5. Define noise figure.
6. Define noise equivalent bandwidth.
7. Define a random variable. Specify the sample space and the random variable for a coin tossing experiment.
8. What is white noise? Give its characteristics.
9. When is a random process called deterministic?
10. Define flicker noise.
11. State the reasons for higher noise in mixers.

Part-B : (16 Marks)
1. Derive the effective noise temperature of a cascade amplifier and explain how various noises are generated in the method of representing them. (16)
2. Explain the following terms
(i) Random variable
(ii) Random process
(iii)Gaussian process (16)
3. Explain how various noises are generated and the method of representing them. (16)
4. Write notes on noise temperature and noise figure. (16)
5. Derive the noise figure for cascade stages. (16)
6. What is narrowband noise? Discuss the properties of the quadrature components of a narrowband noise? (16)
7. Write short notes on thermal noise and short noise. (16)
8. Explain in detail about white and filtered noise. (16)