$($a$)$ Consider a refrigerator control system. Identify the controlled variable, controlling variable and setpoint in the refrigerator control system and define elements of the control system in terms of the refrigerator components.

$[3$ Marks$]$

$($b$)$ Suppose the temperature range $20$ to $120C$ is linearly represented by the standard current range of $4$ to $20mA.$ What current will result from $66C?$ What temperature does $6\mathrm{.}5mA$ represent? $[2$ Marks$]$

Q$.2$ Set. $($A$)$ The following jobs are waiting to be processed at a drilling centre. Today is day $25.$ Using the shortest processing time, longest processing time, last come first serve and critical ratio scheduling rule, in what sequence would the jobs be processed?

$5$

$\backslash$table$[[$Job$,$Date Job received,Production days needed,Job Due date$],[1,21,3,26],[2,22,2,29],[3,22,4,30],[4,24,5,32],[5,25,2,34]]$

Q$.2$ Set. $($B$)$ The following jobs are waiting to be processed at a shaping machine. Today is day $50.$ Using the shortest processing time, longest processing time, last come first serve and critical ratio scheduling rule, in what sequence would the jobs be processed?

$[5]$

$\backslash$table$[[$Job$,$Date Job received,Production days needed,Job Due date$],[1,42,6,52],[2,44,5,58],[3,43,8,60],[4,48,12,64],[5,50,7,68]]$