In the lesson's kettle model, which action is the process?

• Heating the water inside
• Supplying electrical energy
• Delivering the hot water

Which labels describe the three main stages in a basic product system model?

• Input, process and output
• Purchase, storage and price
• Shape, colour and material

What does feedback do in a running system?

• Adds an output without measuring any result
• Stores a finished product without changing control
• Uses measured results to adjust control

A thermostat controls a heater to keep a room near a chosen temperature. How does it use feedback?

• It follows a fixed timer without measuring the room
• It compares room temperature with the chosen value
• It heats the room directly without using the heater

Which row models a toaster's main inputs, process and food output?

• Bread and electricity; heating; toast
• Toast and electricity; cooling; bread
• Bread and electricity; freezing; ice

A kettle and a phone app can both be modelled with input, process and output stages.

Circle one:   True   False

In a greenhouse model, the fan lowers inside temperature. A sensor measures that temperature, and the controller adjusts fan speed to keep it near a chosen value. Between tests, the team redesigns the blades using test results. Classify the fan-speed adjustment and blade redesign.

• Fan-speed adjustment is iteration; blade redesign is feedback.
• Both are feedback because each change uses recorded test results.
• Fan-speed adjustment is feedback; blade redesign is iteration.

In a music-system simulation, checks show correct input data and a clean processed signal reaching the speaker. The speaker produces distorted sound. Which stage should be investigated first?

• The input stage, where the data enters
• The output stage, which produces the sound
• The process stage, which supplies the signal