B.Sc Nautical Science
Subject Code: UG21T2404
Subject : Nautical Electronics III
Answer Any Seven
1.(a)Explain the terms sampling, quantisation ,quantizing error and encode.
(5 Marks)
(b) What is straight receiver? What are the drawbacks of a straight receiver? How are they overcome in a TRF? Explain TRF receiver. (5 Marks)
- (a) Explain pulse amplitude modulation with neat waveform and block diagram (5)
(b) A message signal has a sine tone of 500Hz, sound tone of 1000Hz and a high frequency component of 2000Hz. What is minimum sampling frequency? (5)
3.(a) Explain PCM generation and demodulation with suitable block diagram (6)
(b) For a minimum line speed with 8bit PCM for speech signal of 1V
calculate resolution and quantisation error (4)
- (a)Explain the working of a communication receiver with help of a block diagram. (5 Marks)
(b)With the aid of appropriate diagram, explain the operation of Yagi Uda
antenna. (5 Marks)
5.(a) With neat sketch explain a tuned RF receiver (5)
(b) Explain a super hetro-dyne receiver (5)
6.(a) Briefly explain types of noises (5)
(b) An amplifier with a bandwidth of 20MHz has a 10kΩ input resistor. What is the rms noise voltage at the input to this amplifier if ambient temperature is 27°C (3)
(c) Define signal to noise ratio (2)
7.(a)Explain a transmission line with proper equivalent circuit (6)
(b) Define characteristic impedance of a transmission line (4)
8.(a)Explain resonant and non resonant antennas using proper radiation patterns (6)
(b) If antenna resistance is 100Ω and radiation refficiency is 75%, what is the antenna radiation resistance (4)
- (a) Explain a basic radar system with neat block diagram. (6)
(b) Calculate maximum range of a radar system which operates at 3cm wavelength with a peak pulse power of 500kW, if its minimum receivable power is 10-13W, the capture area of its antenna is 5m2 and the radar cross sectional area of the target is 20m2. (4)