Question Paper: Priniciples of Communication Engineering Question Paper - Dec 18 - Electronics And Telecomm (Semester 4) - Mumbai University (MU)
Priniciples of Communication Engineering - Dec 18
Electronics And Telecomm (Semester 4)
Total marks: 80
Total time: 3 Hours
(1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Draw neat diagrams wherever necessary.
Q1 Solve any Four
Modulation Index for AM should be less than one. Justify/Contradict.
What is aliasing? How it can be prevented?
Why AGC is required in radio receivers?
Justify, why FM is more immune to noise?
Define noise figure and noise factor.
State and prove sampling theorem for low pass bandlinited signals.
One input to AM modulation is 800 KHz carries with an amplitude of 10 $V_p$. The second input is 10KHz modulating signal that is of sufficient amplitude to cause a change in o/p wave of $\pm$5.5 $V_p$. Determine
Upper and lower side frequency
Modulation co-efficient and percent modulation
Draw o/p frequency spectrum
Draw modulated wave showing maxima and minima of waveforms
Explain the operation of Foster Seeley discriminator with the help of circuit diagram and phasor diagram.
Explain the working of stabilized reactance modulator with suitable diagram.
With help of neat diagram and waveforms explain generation and demodulation of PWM.
Explain phase shift method for suppression of unwanted carrier with neat block diagram.
Explain the following with reference to AM receiver
Three point tracking
Image frequency rejection ratio
Explain Indirect FM transmitter with suitable diagram.
Q6 Write short note on (any four)
Vestigial side band transmission (VSB) and its application
$\mu$-law and A-law companding
Frequency division Multiplexing (FDM)
Amplitude limiting and thresholding.
Pre emphasis and de-emphaisis circuits and its need