CIE IGCSE | TOPIC 3 ASSESSMENT
HARDWARE: END OF TOPIC REVIEW
Check your understanding of CPU architecture, input and output devices, sensors, storage and network hardware. Work independently before checking your answers.
BEFORE YOU BEGIN
Suggested time: 25–35 minutes. Complete sections A and B without notes. Write section C answers in your exercise book before revealing the marking guidance.
Sections A and B provide an automatic score out of 11, one point for each fully correct item. Section C has 10 suggested written marks, assessed separately. These are original practice questions, not an official Cambridge paper or grade boundary.
For calculations, show working in your book and enter the answer in the unit requested. Calculator use can follow your teacher’s instructions. Your answers remain only while this page is open.
C | EXAM-STYLE WRITING
Write in your exercise book before revealing the guidance. Section C assesses subject knowledge and gives you practice expressing it clearly. The first table reproduces the command-word meanings supplied from the Cambridge syllabus. The second gives practical writing guidance for this review.
| CIE command word | Meaning from the specification |
|---|---|
| Calculate | work out from given facts, figures or information |
| Compare | identify/comment on similarities and/or differences |
| Define | give precise meaning |
| Demonstrate | show how or give an example |
| Describe | state the points of a topic / give characteristics and main features |
| Evaluate | judge or calculate the quality, importance, amount, or value of something |
| Explain | set out purposes or reasons / make the relationships between things clear / say why and/or how and support with relevant evidence |
| Give | produce an answer from a given source or recall/memory |
| Identify | name/select/recognise |
| Outline | set out the main points |
| Show (that) | provide structured evidence that leads to a given result |
| State | express in clear terms |
| Suggest | apply knowledge and understanding to situations where there are a range of valid responses in order to make proposals / put forward considerations |
The command applies to the subject context. A brief identification does not need an essay; an explanation needs accurate links. Use the guidance below for the four commands in this written review.
| Command word | What your answer should do | Useful writing pattern |
|---|---|---|
| Describe | State the main features or relevant points; for a process, make the sequence clear. | First… Next… Finally… |
| Explain | Give reasons, purposes or clear relationships, supported by relevant subject knowledge. | …because…; therefore…; resulting in…; leading to… |
| Compare | Identify similarities and/or differences, addressing both things on the same basis. | Both…; whereas…; unlike… |
| Evaluate | Make a reasoned judgement about suitability or value in the given context. | A benefit is…; however…; therefore, for this purpose… |
BUILD A CLEAR EXPLANATION
Point → reason or mechanism → consequence. Connectives help show the relationship, but the technical link must be accurate. Adding “because” to an unsupported claim does not make it a good explanation.
Thin answer: “The fan switches on.”
Developed answer: “Because the processor detects a temperature above the threshold, it sends an output signal to switch on the fan, resulting in cooling.”
Use because or because of to introduce a cause; therefore, resulting in or leading to to show a consequence. For comparison, use both and whereas. For evaluation, use however and finish with a justified judgement.
Write enough relevant detail for the marks available. Clear, concise sentences are better than padding. These are writing supports, not compulsory phrases or separate official language marks.
12 | FETCH, DECODE, EXECUTE
[3 suggested marks]
Describe the fetch–decode–execute cycle, including the roles of the PC, MAR, MDR and CIR during the fetch.
Sample answer: First, the address in the PC is copied to the MAR and the control unit requests a memory read. The instruction is returned to the MDR and copied to the CIR; the PC advances to the next instruction. Next, the control unit decodes the instruction. Finally, the CPU carries out the specified operation, using the ALU if arithmetic or logic is required, and the cycle repeats.
- PC address transferred to MAR and memory read requested: one mark.
- Instruction transferred through MDR to CIR and PC advanced: one mark.
- Decode and execute correctly described: one mark.
Writing focus: use a clear sequence and distinguish an address from the instruction stored at that address.
13 | AUTOMATIC GREENHOUSE
[3 suggested marks]
A greenhouse controller switches a fan on when the measured temperature exceeds a set threshold. Explain how a temperature sensor, processor and actuator work together to control the fan.
Sample answer: The temperature sensor provides a reading of the greenhouse temperature. The processor compares the reading with the set threshold, so it can decide whether cooling is required. Because the temperature is above the threshold, the processor sends an output signal through suitable control circuitry to an actuator that switches the fan on, resulting in cooling. Further readings allow the controller to respond as conditions change.
- Sensor reading linked to measured temperature: one mark.
- Processor comparison linked to the decision: one mark.
- Output/actuator linked to fan operation and cooling: one mark.
Writing focus: link each component to the next. The sensor supplies input; it does not itself make the program’s decision.
14 | RAM AND ROM
[2 suggested marks]
Compare RAM and ROM in terms of what happens when power is removed and their typical uses in a computer.
Sample answer: RAM is volatile, so its contents are lost when power is removed, whereas ROM is non-volatile and retains its contents. RAM holds programs and data currently in use, while ROM typically holds firmware or startup instructions.
- Linked comparison of volatility: one mark.
- Linked comparison of typical purpose: one mark.
Writing focus: address both memories on each point. Some firmware storage can be updated, so avoid claiming every form of ROM can never change.
15 | SCHOOL VIDEO STORAGE
[2 suggested marks]
A school media team needs to share large video files from home and school, but its internet connection is sometimes unreliable. Evaluate using cloud storage instead of relying only on a local external drive. Give a justified judgement.
Sample answer: Cloud storage allows authorised team members to access and share the files from different locations. However, uploading and downloading large videos takes time, and an unreliable connection can prevent access to files that are not saved locally. Therefore cloud storage is useful for collaboration, but keeping suitable local copies for editing and a separate backup would better meet the team’s need for reliable access.
- Collaboration benefit weighed against connection/transfer limitations: one mark.
- Contextual judgement supported by the trade-off: one mark.
Writing focus: finish with a reasoned recommendation. Cloud data is stored on physical remote servers; synchronisation alone is not a guarantee of a recoverable backup.
CHECK YOUR WRITTEN COMMUNICATION
- Did I answer the command word, rather than just name facts?
- For explain, did I show an accurate reason or cause-and-effect link?
- For compare, did I address both things on the same point?
- For evaluate, did I weigh relevant factors and justify my judgement?
- Did I use precise terms and connectives naturally, without repeating or padding?
Self-assess using the suggested content marks, keeping the written total separate from your automatic score. Use the writing checklist to improve an answer rather than adding unofficial language marks.
YOUR NEXT REVISION STEP
Submit sections A and B to see suggested lessons to revisit.
For written work, revisit CPU components and the cycle, sensors and control and storage where needed.
This review samples the topic. Also revisit input and output device mechanisms, instruction sets, embedded systems, magnetic/optical/solid-state storage, MAC and IP addresses and routers using the full Topic 3 revision page.
Choose two weak areas, revisit their explanations and attempt a fresh example. Repeating these questions after feedback shows learning, rather than an independent assessment.