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Practise 30 exam-style questions on Secondary storage: magnetic, optical and solid-state for Cambridge IGCSE Computer Science (Paper 1). Write your answer as you would in the exam and get it marked in seconds against the mark scheme, point by point, with an AI tutor on hand if you get stuck.
Here are 4 of the questions in this topic, each with a model answer, an explanation of why it earns the marks and the mark scheme an examiner would use.
Name the two types of technology used to make flash memory.
NAND and NOR.
Flash memory is built using either NAND or NOR technology, named after the way the transistors in each cell are connected. NAND is the type used in most SSDs, SD cards and USB flash drives.
NAND and NOR
both needed for the mark
Describe the difference between a pit and a land on an optical disc.
A pit is a tiny indentation (or burnt spot) in the surface of the disc, which scatters the laser light. A land is a flat area between the pits, which reflects the laser light back to the sensor.
Pits and lands are the two kinds of area along the spiral track. Because they reflect light differently, a laser and sensor can tell them apart, and the pattern is converted into binary data.
A pit is a tiny indentation/burnt area in the surface (which scatters the laser light)
A land is a flat/unburnt area of the surface (which reflects the laser light back)
A sales representative travels to meet customers every day and uses her laptop on trains and in cars.
Explain why a solid-state drive (SSD) would be more suitable than a hard disk drive (HDD) for her laptop.
An SSD has no moving parts, so it is far less likely to be damaged by knocks and vibration on trains and in cars. It uses less power, so her battery lasts longer while she is travelling, and it is lighter, making the laptop easier to carry. It also has faster access times, so the laptop starts up and opens presentations quickly.
The advantages of solid-state storage over magnetic storage come from having no moving parts: it is robust, fast, light and low-power. The best answers link each advantage to the scenario (travel, battery, carrying) rather than listing features.
No moving parts, so more robust / less likely to be damaged by knocks or vibration while travelling
max 3
Uses less power, so the laptop's battery lasts longer away from a power supply
Lighter/thinner, so the laptop is easier to carry
Faster access, so the laptop starts up and opens files more quickly (e.g. in front of customers)
Quieter / produces less heat
Optical discs such as CDs and DVDs used to be a popular way to back up data, but they are now rarely used for this.
Explain why optical discs are less suitable for backing up data than other types of storage.
Optical discs have a very low capacity compared with external hard drives or flash drives, so backing up a modern computer would need many discs. Writing data to them is slow, and recordable discs can only be written once, so they cannot be updated as files change. Many modern laptops no longer have an optical drive, and discs are easily scratched, which can make the backup unreadable.
Optical storage remains useful for distributing films, games and software, but for backups its small capacity, slow writing and fragility are major drawbacks. External HDDs, flash drives and cloud storage offer far more capacity with less effort. Good answers give specific weaknesses rather than saying optical discs are 'old'.
Low capacity compared with HDDs/flash drives, so many discs would be needed for a large backup
max 4
Slow to write data
Many modern computers/laptops do not have an optical drive
Discs are easily scratched or damaged, which can make the data unreadable
Recordable (R) discs can only be written once, so they cannot be updated/reused
Other options (external HDD, USB flash drive, cloud storage) have a lower cost per GiB / are more convenient / can be updated automatically
Ready to try the rest? Every answer you write is marked against the mark scheme, so you can see exactly where the marks are.
Hi! Stuck? Ask me for a hint and I’ll help you work it out. Once you’ve checked your answer I can explain exactly where the marks are.
