JNTU
JNTU B.Tech III PRINCIPLES OF COMMUNICATIONS Previous Question Paper (November/December - 2017 - R13)
Part A is compulsory which carries 25 marks. Answer all questions in Part A. Part B consists of 5 Units. Answer any one full question from each unit. Each question carries 10 marks.
Part A
Define shot noise.
Answer
Shot noise is a type of electronic noise that occurs when the finite number of particles (such as electrons) that carry energy is small enough to give rise to detectable statistical fluctuations in a measurement, such as current in an electronic circuit or the optical power in an optical device.
Draw the block diagram of electrical communication system and define each block.
Answer
The block diagram consists of: Information Source → Input Transducer → Transmitter → Channel → Receiver → Output Transducer → Destination.
- Information Source: Originates the message signal.
- Input Transducer: Converts non-electrical physical quantities into electrical signals.
- Transmitter: Processes the signal for efficient transmission (e.g., modulation, amplification).
- Channel: The medium through which the signal travels.
- Receiver: Extracts the original signal from the received waveform.
- Output Transducer: Converts the electrical signal back to the original physical form.
Define modulation index.
Answer
Sign in to view the complete answer paper.
Define narrow band FM.
Answer
Sign in to view the complete answer paper.
What is pulse width modulation?
Answer
Sign in to view the complete answer paper.
Define time division multiplexing
Answer
Sign in to view the complete answer paper.
List the advantages of digital communication
Answer
Sign in to view the complete answer paper.
What is incoherent reception?
Answer
Sign in to view the complete answer paper.
Define entropy.
Answer
Sign in to view the complete answer paper.
What is error control coding?
Answer
Sign in to view the complete answer paper.
Part B
Explain thermal agitation noise and transit time noise in detail.
Answer
Sign in to view the complete answer paper.
Briefly explain signal to noise ratio and noise figure.
Answer
Sign in to view the complete answer paper.
In detail explain the steps involved in calculation of noise figure.
Answer
Sign in to view the complete answer paper.
Briefly explain industrial noise and atmospheric noise.
Answer
Sign in to view the complete answer paper.
What is angle modulation? With the help of necessary equations explain phase modulation.
Answer
Sign in to view the complete answer paper.
Explain the different type of amplitude modulation.
Answer
Sign in to view the complete answer paper.
Calculate the percentage power saving when the carrier and one of the sidebands are suppressed in an AM wave modulated to a depth of i) 100 percent ii) 50 percent
Answer
Sign in to view the complete answer paper.
With the help of necessary equation explain product demodulation of SSB SC.
Answer
Sign in to view the complete answer paper.
Explain the process of generation of PWM with neat diagrams.
Answer
Sign in to view the complete answer paper.
Define Nyquist rate and explain the importance of Nyquist rate in sampling theorems.
Answer
Sign in to view the complete answer paper.
Explain Frequency Division Multiplexing in detail.
Answer
Sign in to view the complete answer paper.
Explain the concept of Asynchronous multiplexing.
Answer
Sign in to view the complete answer paper.
Draw the block diagram of the DPSK modulator.
Answer
Sign in to view the complete answer paper.
Describe the μ-Law and A-Law in PCM.
Answer
Sign in to view the complete answer paper.
Draw the block diagram of M-ary PSK system and explain its operations.
Answer
Sign in to view the complete answer paper.
Explain coherent and incoherent reception in detail.
Answer
Sign in to view the complete answer paper.
What is CRC? If the polynomial for CRC code is
Answer
Sign in to view the complete answer paper.
Explain the Shannon fano coding with example.
Answer
Sign in to view the complete answer paper.
What are convolution codes explain in detail.
Answer
Sign in to view the complete answer paper.
Following are the symbols and the respective output probability for a discrete memory less source. Compute the Huffman code for the source.
Answer
Sign in to view the complete answer paper.