26. How many megabytes are there in 3 GB?
- 300
- 30,720
- 3072
- 3000
Answer: C) 3072
Explanation: 3 × 1024 = 3072 MB.
MCQs / Computer Science / Storage Units and Memory
Storage Units and Memory MCQs — Computer Science (page 2)
51 multiple-choice questions on Storage Units and Memory from Computer Science, each with the correct answer and, where available, a teacher's explanation. Read through them to revise the chapter, then practise the same questions one by one to test yourself.
27. Which statement about RAM and ROM is correct?
- RAM is read-write and volatile; ROM is read-only and non-volatile
- RAM is read-only; ROM is read-write
- Both are volatile
- Both are secondary storage
Answer: A) RAM is read-write and volatile; ROM is read-only and non-volatile
Explanation: This is the key difference.
28. Which RAM must be refreshed thousands of times per second?
- ROM
- EPROM
- DRAM
- SRAM
Answer: C) DRAM
Explanation: DRAM capacitors leak charge and need refreshing.
29. Which is an advantage of flash storage?
- Unlimited write cycles
- Needs a laser
- Volatile memory
- No moving parts, so it is durable and fast
Answer: D) No moving parts, so it is durable and fast
Explanation: Flash is solid-state.
30. RAM is:
- read only
- volatile
- non-volatile
- a secondary storage device
Answer: B) volatile
Explanation: RAM loses its contents when power is switched off.
31. A USB flash drive stores data in:
- flash memory
- vacuum tubes
- optical pits
- magnetic platters
Answer: A) flash memory
Explanation: It is a solid-state device.
32. EEPROM is erased:
- by breaking the chip
- electrically
- with ultraviolet light
- it cannot be erased
Answer: B) electrically
Explanation: EEPROM = Electrically Erasable PROM.
33. NAS stands for:
- National Archive Storage
- Network Area Server
- New Access System
- Network Attached Storage
Answer: D) Network Attached Storage
Explanation: A storage device attached to a network for shared use.
34. A nibble is equal to:
- 1024 bytes
- 8 bits
- 2 bytes
- 4 bits
Answer: D) 4 bits
Explanation: Half a byte.
35. CD-R discs can be written:
- only by the factory
- never
- once
- unlimited times
Answer: C) once
Explanation: R = recordable once (WORM).
36. A plastic card with an embedded microchip is a:
- magnetic tape
- smart card
- floppy disk
- CD-R
Answer: B) smart card
Explanation: ATM chip cards and SIM cards are smart cards.
37. ROM is:
- volatile
- non-volatile
- a type of hard disk
- erased on every shutdown
Answer: B) non-volatile
Explanation: ROM keeps its contents without power.
38. 1 GB is equal to:
- 1024 TB
- 1024 KB
- 1024 MB
- 1000 KB
Answer: C) 1024 MB
Explanation: 1 GB = 1024 MB.
39. Concentric circles on a disk surface are called:
- clusters
- pits
- tracks
- sectors
Answer: C) tracks
Explanation: Tracks are circular paths.
40. Cache memory is usually made of:
- magnetic tape
- SRAM
- DRAM
- EPROM
Answer: B) SRAM
Explanation: SRAM is fast and needs no refresh.
41. One character such as "A" usually needs:
- 4 bytes in all cases
- 1 byte
- 1 KB
- 1 bit
Answer: B) 1 byte
Explanation: In ASCII, one character uses one byte.
42. RAID 0 uses:
- tape backup
- parity on one disk
- striping without redundancy
- mirroring
Answer: C) striping without redundancy
Explanation: RAID 0 splits data across disks for speed.
43. The BIOS that starts the computer is stored in:
- ROM
- cache
- RAM
- registers
Answer: A) ROM
Explanation: Firmware/BIOS is stored in ROM (flash).
44. A standard CD can store about:
- 4.7 GB
- 700 MB
- 1 TB
- 25 GB
Answer: B) 700 MB
Explanation: CDs hold about 650–700 MB.
45. PROM can be programmed:
- only once
- only by the CPU
- unlimited times
- with ultraviolet light
Answer: A) only once
Explanation: Programmable ROM is written once.
46. RAID 1 uses:
- no disks
- striping only
- mirroring
- optical discs
Answer: C) mirroring
Explanation: Data is copied identically on two disks.
47. A hard disk stores data:
- on paper
- in vacuum tubes
- optically
- magnetically
Answer: D) magnetically
Explanation: Platters are coated with magnetic material.
48. Optical discs are read using a:
- magnet
- electron gun
- laser
- needle
Answer: C) laser
Explanation: Laser light reflects from pits and lands.
49. The time taken to move the read/write head to the correct track is:
- rotational delay
- seek time
- transfer time
- boot time
Answer: B) seek time
Explanation: Seek time is the head-movement time.
50. When the CPU finds the required data in cache, it is called a:
- seek
- cache hit
- page fault
- cache miss
Answer: B) cache hit
Explanation: A hit avoids accessing slower RAM.
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