To decrease the buffer size, the frame size is halved. In this case the

efficiency of the line utilisation between stations A and B will:

$($a$)$ decrease $($b$)$ increase $($c$)$ stay the same $($d$)$ neither a$,$ b or c

$11\mathrm{.}2$

$($a$)$

$($b$)$

$($C$)$

$($d$)$

$12)$ Longitudinal Redundancy Check $($LRC$)$ is used to protect the

following data:

$10101001$

$00111001$

$1101110111100111$

The VRC bits will be given by:

$($a$)$

$01010101($b$)10101010($c$)10111011($d$)10111010$

$12\mathrm{.}1($a$)$

$($b$)$

$($c$)$

$($d$)$

The efficiency of this code is:

$($a$)$

$10\%$

$($b$)80\%($c$)90\%($d$)100\%$

$12\mathrm{.}2($a$)$

$($b$)$

$($c$)$

$($d$)$

$13)$ A communication system uses a CRC$-32$ code. This CRC code

will detect:

$($a$)$ all bit errors $($b$)$ all error bursts greater than $33$ bits $($c$)$ all error

bursts less than $34$ bits $($d$)$ most error burst greater than $32$ bits

$13\mathrm{.}1($a$)$

$($b$)$

$($c$)$

$($d$)$