Question1) State with reasons whether the following statements are True or False.
i) The problem posed by large antenna size in case of audio communication can be solved by amplification process.
ii) 20 dB-Hz bandwidth corresponds to 1000 Hz.
iii) The load impedance of an open ended transmission line is less than 400?.
iv) The AM and FM demodulators are essentially the same except for their frequency bandwidth.
v) FDM and WDM are essentially the same.
vi) The only advantage of satellite radio transmission is its digital signal handling capacity.
vii) H-plane T structure can be used for summing two signals.
viii) The best method of joining the two optical fibre is soldering.
ix) Memory in a computer is a peripheral device.
x) At present there are only 7 generic top-level domains names in use.
Question2)
a) Hindi language has about 50 alphabets (10 vowels and 40 consonants). Show that efficiency of a binary coding system used to represent them is more than that used for coding the English language alphabets.
b) An analog triangular 1 KHz signal is sampled at 8 kbps. Draw the essential circuit and output waveform (with timescale), if peak signal amplitude is 4mV.
Question3)a) What is varactor diode? How could it be used in the frequency modulator circuit?
b) Which type of shift keying technique is used in two tone modulation for code transmission? How is it beneficial than the other type of keying?
Question4) a) Describe the working of electronic exchange with the help of a block diagram.
b) What is CDMA? Describe how same radio frequency could be used by multiple users in this case.
Question5)a) In a radio transmitter an antenna of 100?load resistance is to be connected to a power output stage. The supply voltage is 20V. Design a matching circuit (L-network) to deliver 5W RF power output at 25 MHz.
b) Compare the analog and digital television.
Question6)a) Describe the construction of a tunnel diode used in microwave circuits. Why is it necessary to have heavy doping?
b) Compare the strategies used for data compression in communication networks.
Question7)a) Write the step-wise instructions to add the numbers stored at memory locations A and B, then subtract number stored at C from this result and store the answer in memory location D.
b) Compare the different network topologies on the basis of their ruggedness, complexity and cost.
Question8)a) Justify the need of standard network protocols. Compare the OSI with TCP/IP reference models.
b) Describe, how the Bluetooth connects different devices. How is the interference between devices prevented