problem 1: State with reasons whether the given statements are true or false:

a) The problem posed by large antenna size in case of audio communication can be solved by the amplification process.

b) 20 dB-Hz bandwidth corresponds to 1000 Hz.

c) The load impedance of an open ended transmission line is less than 400?.

d) The AM and FM demodulators are in essence the same except for their frequency bandwidth.

e) FDM and WDM are in essence the same.

f) The only benefit of satellite radio transmission is its digital signal handling capacity.

g) H-plane T structure can be employed for summing two signals.

h) The best method of joining two optical fiber is soldering.

i) Memory in a computer is a peripheral device.

j) At present there are only seven generic top-level domains names in use.

problem 2:

a) Hindi language has around 50 alphabets (10 vowels and 40 consonants). Show that the effectiveness 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 the output waveform (with timescale), if peak signal amplitude is 4mV.

problem 3:

a) An electromagnetic wave is illustrated as:

Find out the phase vector, wavelength, phase velocity and time average Poynting vector.

b) Describe, how a transmission line segment can be employed as a filter.

problem 4:

a) What do you mean by the term varactor diode? How can it be employed in a frequency modulator circuit?

b) Which kind of shift keying method is used in two tone modulation for code transmission? How is it advantageous than the other kind of keying?

problem 5:

a) Describe the working of electronic exchange with the help of a block diagram.

b) What do you mean by the term CDMA? Describe how same radio frequency can be employed by multiple users in this case.

problem 6:

a) In a radio transmitter an antenna of 100? load resistance is to be joined to a power output phase. 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.

problem 7:

a) Describe the construction of a tunnel diode used in microwave circuits. Why is it essential to have heavy doping?

b) Compare the strategies employed for data compression in communication networks.

problem 8:

a) prepare the step-wise instructions to add the numbers stored at memory locations A and B, then subtract the number stored at C from this result and store the answer in memory location D.

b) Compare the various network topologies on the basis of their ruggedness, complexity and cost.

problem 9:

a) Justify the requirement of standard network protocols. Compare the OSI with TCP/IP reference models.

b) Describe, how the Bluetooth connects various devices. How is the interference between the devices prevented?