UGCNET CSE December 2022: 34

Question

 

A Computer on a $10 \mathrm{Mbps}$ network is regulated by a token bucket. The token bucket is filled at a rate of $2 \mathrm{Mbps}$. It is initially filled to capacity with $16$ megabits. What is the maximum duration for which the computer can transmit at the full $10 \mathrm{Mbps}$?

• A. $1.6$ seconds
• B. $2$ seconds
• C. $5$ seconds
• D. $8$ seconds

(Option $1[39433]) 1$
(Option $2[39434]) 2$
(Option $3[39435]) 3$
(Option $4[39436]) 4$

Answer Given by Candidate : $2$

Answer 1

As given bucket capacity is more than the date to be transmitted, 
given input rate = 2 Mbps , Output rate = 10 Mbps , Data to be transmitted = 10 Mbps , Capacity = 16 Mb (initially Filled)

so Duration for which the bucket will empty at max output rate (given 10 Mbps) 
= Capacity /  (Max o/p rate - Input rate) 
= 16 / (10-2)
= 2 Seconds

what 2 seconds means that in 2 second , 10 Mb data will be transferred. 
so answer = 2 sec


further analysis, 
this 2 seconds is the time for which data will be transmitted at the max output rate , i.e. 10 Mbps , 
2 seconds * 10 Mbps 
= 20 Mb MAX DATA could be transferred in those 2 seconds.

but we only need to transfer 10 Mb , so why answer is not 1 second  ?
because bucket is initially filled, so we also need to consider the input rate and out put rate , so effective rate become Output rate - Input rate. 

hope this helps