An automated commercial greenhouse irrigation controller uses an algorithm to determine the volume of liquid fertilizer (in litres) to deliver to a crop zone based on the average ambient temperature and soil moisture levels.
Using the pseudocode below, complete the trace table.
avgTemp ← USERINPUT
moisturePct ← USERINPUT
irrigationVol ← 0.0
msgNoIrrig ← "Irrigation suspended"
msgManual ← "Requires manual check"
IF avgTemp ≥ 15.0 AND moisturePct < 80.0 THEN
IF moisturePct < 30.0 THEN
irrigationVol ← 12.5
OUTPUT irrigationVol
ELSE IF moisturePct < 60.0 THEN
irrigationVol ← (85.0 - moisturePct) * 0.2
OUTPUT irrigationVol
ELSE
OUTPUT msgNoIrrig
ENDIF
ELSE
OUTPUT msgManual
ENDIF
| Input value of avgTemp | Input value of moisturePct | Output |
|---|---|---|
| 22.0 | 25.0 | |
| 18.0 | 45.0 |
208 exam-style questions on AQA GCSE Computer Science Representing algorithms. Each one has a worked solution and a mark scheme showing where the marks go.