An alarm sounds when certain conditions occur in a nuclear reactor. For
Examiner's
Use
The output, X, of a logic circuit that drives the alarm must have a value of 1 if:
either carbon dioxide pressure too low and temperature < = 300°C
or water pressure > 10 bar and temperature > 300°C
The inputs to the system are:
Input Binary Condition
0 carbon dioxide pressure too low
P
1 carbon dioxide pressure acceptable
0 temperature > 300°C
T
1 temperature < = 300°C
0 water pressure > 10 bar
W
1 water pressure < = 10 bar
(a) Draw the required logic circuit using AND, OR and NOT gates only.
[5]
(b) Complete the truth table for the above system.
P T W X
0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1
[4]
CLES 2012 0420/11/O/N/12
Examiner's
Use
The output, X, of a logic circuit that drives the alarm must have a value of 1 if:
either carbon dioxide pressure too low and temperature < = 300°C
or water pressure > 10 bar and temperature > 300°C
The inputs to the system are:
Input Binary Condition
0 carbon dioxide pressure too low
P
1 carbon dioxide pressure acceptable
0 temperature > 300°C
T
1 temperature < = 300°C
0 water pressure > 10 bar
W
1 water pressure < = 10 bar
(a) Draw the required logic circuit using AND, OR and NOT gates only.
[5]
(b) Complete the truth table for the above system.
P T W X
0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1
[4]
CLES 2012 0420/11/O/N/12
