(a) Give two differences between RAM and ROM. [2]
(b) A photographer needs to store images on a portable device while working outdoors. State the most suitable type of secondary storage and justify your choice. [3]
(c) Give one reason why a computer needs secondary storage as well as main memory. [1]
- (a) Any two differences (1 mark each; must be comparative or describe both): RAM is volatile / loses its contents when power is off, ROM is non-volatile; RAM can be read from and written to, ROM is read-only (cannot normally be changed); RAM stores the programs / data currently in use, ROM stores the start-up (boot) instructions / BIOS; RAM usually has a larger capacity than ROM. First difference(1)
- (a) Second, different difference from the list above(1)
- (b) Solid state (flash memory); accept SSD / memory card / SD card / USB flash drive. Reject magnetic / hard disk drive and cloud storage (no marks for the choice or its justifications)(1)
- (b) Any two justifications from (1 mark each), only if solid state was chosen: no moving parts / robust / durable / shock-resistant so not damaged if dropped or knocked outdoors (allow 'no moving parts' alone); small / compact / lightweight so easy to carry; low power use so battery lasts longer; fast access / read-write speed. First justification(1)
- (b) Second, different justification from the list above; reject 'large capacity' or 'cheap' as a reason(1)
- (c) Either: main memory (RAM) is volatile so data / programs would be lost when the power is turned off, so non-volatile secondary storage is needed to keep them permanently (long term); or: main memory is not large enough to hold all the programs and data that need to be stored. Either half of the volatility point on its own is enough (e.g. 'RAM is volatile' or 'secondary storage keeps data when the power is off')(1)
- Answer: (a) RAM volatile & read/write; ROM non-volatile & read-only (b) solid state – robust, portable (c) to store data permanently when power is off
- Examiner tip: Justifications must link to the scenario – portable and outdoors means robustness and size, not capacity.