Networking subjective question for competitive exam(2)

Q1 In a fully connected mesh network with 10 computers,total number of cables are required and number of ports are required for each device. .

number of ports=n-1
                            =10-1=9
number of cables=n(n-1)/2=(10*9)/2=45

Q2. Assume that we need to download text documents at the rate of 100 pages per minute.A page is an average of 24 lines with 80 characters in each line and each character requires 8 bits.Then the required bit rate of the channel is.

Bit rate is the trasmission of number of bits per second.
Baud rate is defined as the number of signal units per second.

   Bit rate=Baud rate* the number of bit per baud
   Baud rate=Bit rate/number of bit per baud

       =100*24*80*8/60=25600bps=25.6kbps.

             

Q3. The period of a signal is 100ms.Then the frequency of this signal in kilohertz is

f=1/T
f=1/100ms=1/100*10^-3sec=1000/100=10sec hz=10/1000khz=10^-2khz

Q4.You are designing a link layer protocol for a link with badwidth of 1Gbps over a fiber link with length of 800km.Assume the speed of light in the medium is 200000km/second. What is the propagation delay in this link?

Propagation delay=Distance/speed
                               =800/200000=4*10^-3
                                =4milisec.        

Q5.You are designing a link layer protocol for a link with badwidth of 1Gbps over a fiber link with length of 1600km.Assume the speed of light in the medium is 100000km/second. What is the propagation delay in this link?

Propagation delay=Distance/speed
                               =1600/100000=16*10^-3
                                =16milisec.