Show model answer and explanation
1
29 exceeds28.
Class 7 · English Medium · Pearson Edexcel · General science
Forces, energy and electricity
Explain a feedback system and distinguish sensing from action.
Original Kidemy further-topic investigation. This optional lesson is shared by related upper pathways; select suitable depth with a teacher. It does not certify complete grade or board coverage.
Learn the idea
A feedback system measures a quantity, compares it with a target and acts to reduce a difference. A sensor alone does not change the environment. Real systems can respond slowly or overshoot, so repeated observation matters.
Worked example
A fictional greenhouse controller switches a fan on above28 °C and off below26 °C. The gap between thresholds prevents rapid switching around one temperature. This is a paper model, not wiring guidance.
- Define target and thresholds.
- Trace input, stored state and action.
- Explain a delay or alternative cause.
Your written practice
Show your working on paper and enter your answer here. If it does not match, compare the model and try again.
Show model answer and explanation
0
25 is below26.
Show model answer and explanation
temperature sensor
The sensor supplies the measurement.
Write in your own words. A guardian or teacher should review this response.
Show model answer and explanation
The fan keeps its previous state because neither switching threshold is crossed.
Use state and both thresholds.
Write in your own words. A guardian or teacher should review this response.
Show model answer and explanation
The reading may change for other reasons and the fan action needs a comparable observation.
Separate sensing, action and evidence.
Apply the idea
Draw an input–comparison–action loop and trace five temperatures through it.
Review with a guardian or teacher
- Use the stated evidence or givens.
- Show reasoning rather than only a result.
- Review and explain one correction.
Keep your work on paper or in a local file. This page does not upload it or automatically grade the project.
Teacher-led lessons, schedules and prices for this outline are upcoming. You can use any starter practice above now without booking.
Your next step
Solo practice works without an account. Sign in to save a practice record to your learner profile.
Keep practising
Exact lesson links and related activities are labelled separately. Return-to-course links retain your selected learning path.