B.TECH - Semester 4 analog communication Question Paper 2021 (dec)
Practice authentic previous year university questions for better exam preparation.
Sample Questions
- What is image frequency and its rejection ratio?
- Compare the analog modulation schemes $\mathrm{AM}, \mathrm{FM}$ and PM .
- What is the need for pre-emphasis and de-emphasis in FM?
- Wrile shorl noles on shot noise.
- Explain how TDM is accomplished using PAM. 6 What is threshold effect in angle modulation?
- List the sleps for completing a local call in POTS.
- The oulpul current of a 80 percent modulated AM generator is 1.2 A . To what value will this current rise if the generator is simultanemusly modulated by another audio wave, whose modulation index is 0.5 ?
- The equation of a modulated signal is $v=6 \sin \left(10^{7} t+4 \sin 10^{2} t\right)$. Delermine the carrier and modulating signal frequencies, modulation index and bandwidth of the modulated wave. $$ (10 \times 4=40 \text { Marks }) $$ Answer any...
- Explain the generation of DSB-SC AM using balanced modulator. ..... 10 12 (a) Discuss on envelope delection of AM. ..... 5 (b) Write short noles on linee poinl tracking ..... 5 13 Wiln a block diagram, explain the operation of AM Iransmiller. ..... 1...
- Explain the Armstrong melhod of generalion of FM. ..... 10
- (a) A carrier wave has an unmodulated frequency of 6 MHz . Skelch the inslanlaneous frequency lime curve when it is frequency modulated by a 4 kHz square waveform which is varied 5Vp-p aboul zero do value. The frequency devialion constant is 8 kHztvo...
- (b) Discuss about varactor diode modulator. ..... 5
- Discuss the Fosler-Seely discriminalor method of FM delection. ..... 10 Module - III
- Derive the ligure of meril for SSB-SC AM and compare it with slandard AM ..... 10 18 (a) A mixer has a noise frigure of 20 dB and this is preceded by an amplifier thal has a noise ligure of 9 dB and available power gain of 15 dB . Calculate the overa...
- Explain the working of slandard telephone set with block diagram. ..... 10 $$ \{6 \times 10=60 \text { Marks\} } $$