B.TECH - Semester 3 analog communication Question Paper 2021 (oct)
Practice authentic previous year university questions for better exam preparation.
Sample Questions
- If two sine waves are used to amplitude modulate a carrier with modulation index 1,4 and 0.5, calculate folal radialed power.
- Wrile advamage al carrier reinserlion in SSB.
- Explain the effect of noise in angle modulation.
- Write the reason for the use of point conlact didde at higher frequencies in AM defectors
- Explain how conslant inlemediate frequency is achieved in a superheterodyne receiver
- Explain the reason for the use of aulomatic gain control in receivers, Dislinguish between simple AGC and delayed AGC.
- In an $F M$ system, if the maximum value of deviation is 75 kLiz and the maximum modulating frequency is 10 kHz , calculate the bandwidlh of the system using Carson's rule
- With a block diagram show the use of frequency multiplication and mixing to increase the frequency deviation in FM.
- Explain what is Nyquist rate and Nyquist interval
- Explain A-law companding. $$ (10 \times 2=20 \text { Marks }) $$ Answer one full questions oul of two from each Module.
- (a) With block diagtam explain phase shift method for generation of SSB. 10
- (b) Draw circuil diagram and explain working of envelope delector for AM. Draw waveforms at inpul and oulpul. Explain the importance of RC lime conslants for the circuil.
- (a) Draw circuit of balanced modulator using FETs, for generalion of DSB SC. 10
- (b) Write shorl noles on Vestigial Sideband Iransmission: principles, requency spectrum of transmitted TV signal.
- (a) With block diagram explain working or double conversion receiver. 10
- (b) The noise ligure of a receiver's 20 dB and it is fed by a low noise amplifier which has a gain of 40 dB and nolse temperature of 80 K . Calculate the noise lemperature of the receiver and overall noise lemperature of the receiving system. 10
- (a) A radio receiver with equivalent noise bandwidth of 10 kHz has a moise ligure of 20 dB . If the inpul SNR to receiver is 40 dB , delermine the oulpul SNR, What is equivaleni noise temperalure,
- (b) Explain the ellect of noise in DSB SC receivers for AM
- (a) Explain with a circuil diagram the working of varaclor diode modulalor.
- (b) Explain the working or Fosler Seetey discriminalor for demodulation of FM.
- (a) Writh block diagram explain FM stereo broadcast receivers. 10
- (b) Derive equation for frequency modulated wave.
- (a) Derive and plot the effect of sampling on spectrum of signal band limiled to WHIL
- (b) Briefly describe C-message noise weighting and slate ils significance. OR 18 (a) Explain with block diagram sleps inwolved in pulse code modulation. 10
- (b) With block diagram explain working of cordless telephone system. $$ \{4 \times 20=80 \text { Marks }\} $$