Todays Discussion: Computer Networks

Q.Which phenomenon of ofc supports transmission of data?
Ans : Total internal reflection

When incident light is less than critical angle, total internal reflection occurs



Q.Which topology requires a central controller or hub ?

A Mesh topology
B Star topology
C Bus topology
D Ring topology

Answer: B

Q. In a broad sense,  a railway track is an example of
A. Simplex
B.Half-duplex
C.full-duplex
D.all the above

Answer: B


Explanation:

What is Simplex, Half-Duplex & Full-Duplex?

Simplex Simplex is one direction. A good example would be your keyboard to your CPU.  The CPU never needs to send characters to the keyboard but the keyboard  always sends characters to the CPU. In many cases, Computers almost always  send characters to printers, but printers usually never send characters to  computers (there are exceptions, some printers do talk back). Simplex  requires only one lane (in the case of serial). Half-Duplex Half-Duplex is like the dreaded "one lane" road you may have run into at construction sites. Only one direction will be allowed through at a time. Railroads have to deal with this scenario more often since it's cheaper to  lay a single track. A dispatcher will hold a train up at one end of the single  track until a train going the other direction goes through. The only example I  could think of for Half-Duplex is actually a Parallel interface. Even though parallel is eight lanes, data travels through the lanes in the same direction at the same time but never in both directions at the same time. The IEEE-1284 allows printers to send messages to the computer. The printer cannot send these messages while the computer is sending characters but when the computer stops sending characters, then the printer can send messages back. It's kind of like some roads that head into downtown. In the morning, they're one way roads, allowing traffic to go into downtown. In the evening their one way roads, allowing traffic to head out of downtown. The only advantage that Half-Duplex would have is the single lane or single track is cheaper then the double lane or  double track. Full-Duplex Full-Duplex is like the ordinary two-lane highway. In some cases, where traffic  is heavy enough, a railroad will decide to lay a double track to allow trains to pass in both directions. In communications, this is most common with networking. Our fiber optic hubs have two connectors on each port, one for each lane of a two-lane roadway. Full-Duplex fiber is two cables bundled or tied together to form the two-lane roadway. In 100Base-TX, the two lanes are housed in the same jacket. RS232 was also designed to handle Full-Duplex but some of our short haul modems and converters give the user the option to go Half-Duplex or Simplex to  reduce the number of conductors needed to connect between them.

Q.A set of rules that governs data communication
a) Protocols
b) Standards
c) RFCs
d) None of the mentioned

Answer: A


Q.Which device in communication satellite listens to some portion of a spectrum, amplifies the incoming signal, and then rebroadcasts it at another frequency ?

A Transponder
B Repeater
C Gateway
D None of these

Answer: A




GK SESSION


Q. In which sport the term "Bull's Eye" is used ?

A.  Tennis
B.  Golf
C.  Shooting
D.  Chess

Answer: C


Q.Which Indian organisation has designed and build the Dr APJ Abdul Kalam memorial?
[A] Indian Space Research Organisation (ISRO)
[B] Vikram Sarabhai Space Centre (VSSC)
[C] Defence Research and Development Organisation (DRDO)
[D] Bhabha Atomic Research Centre (BARC)

Answer: C