GTU Electronics & Communication - December 2015 Exam Question Paper

GTU Electronics and Communication Engineering (Semester 5)
Electronics & Communication
December 2015

Total marks: --
Total time: --

INSTRUCTIONS
(1) Assume appropriate data and state your reasons
(2) Marks are given to the right of every question
(3) Draw neat diagrams wherever necessary

1(a) State the Parseval's theorem. Verify Parseval's theorem for the signal g(t) = e^-at u(t) (a>0).

7 M

1(b) Draw and explain circuit of envelope detector for AM.

7 M

Solved any one question from Q.2(b) & Q.2(c)

2(a) Derive the Friis's formula for noise factor when amplifiers are in cascade Connection.

7 M

2(b) A receiver has a noise figure of 12 dB, and it is fed by a low-noise amplifier that has a gain of 50 dB and a noise temperature of 90 K. Calculate the noise temperature of the receiver and the overall noise temperature of the receiving system.

7 M

Solved any one question from Q.3 & Q.4

2(c) Draw series tuned circuit and derive the equation for resonant frequency and Q factor.

7 M

3(a) Explain different types of noise related to communication.

7 M

3(b) Explain AGC and discuss difference between simple AGC and Delayed AGC.

7 M

4(a) With respect to receivers explain Image rejection and double spotting in detail.

7 M

Solved any one question from Q.5 & Q.6

4(b) Discuss Quadrature Amplitude Modulation (QAM) with the help of block diagram.

7 M

5(a) An AM broadcast receiver has an IF of 465 KHz and is tuned to 1000 KHz and the RF stage has one tuned circuit with a Q of 50. (a) Find the image frequency; (b) Find the image rejection in decibels.

7 M

5(b) Explain Amplitude modulation with required waveforms. Also give Mathematical representation of amplitude modulated wave.

7 M

6(a) The total power content of an AM signal is 1000 W. Determine the power being transmitted at the carrier frequency when the percentage modulation is 100%

7 M

6(b) Determine the Fourier transform of a gate pulse of unit height, unit width and centred at t=0.

7 M

Solved any one question from Q.7 & Q.8

7(a) Define the following terms related with radio receiver:
(i) selectivity
(ii) fidelity
(iii) sensitivity and gain
(iv) tracking
(v) double

7 M

7(b) Explain pre-emphasis and de-emphasis in relation to FM.

7 M

8(a) Explain the Armstrong method of FM generation with neat diagram.

7 M

8(b) An FM wave is given by e(t) = 20sin(6*10 ⁸ t + 7sin 1250t). Determine (i) carrier frequency (ii) modulating frequency (iii) modulation index and (iv) maximum deviation.

7 M

More question papers from Electronics & Communication

SPONSORED ADVERTISEMENTS