With regard to computer memory, which of the following statement(s) is/are…
2018
With regard to computer memory, which of the following statement(s) is/are TRUE ?
P : Read Only Memory (ROM) is ‘volatile’ memory.
Q : Random Access Memory (RAM) is ‘volatile’ memory.
R : Secondary Memory is ‘volatile’ memory.
Answer: B. Q only — Concept. Volatility is a property of the storage cell itself: it says whether the device needs a continuous supply of electrical power to keep whatever has…
- A.
P only
- B.
Q only
- C.
P and Q only
- D.
P and R only
Show answer & explanation
Correct answer: B
Concept. Volatility is a property of the storage cell itself: it says whether the device needs a continuous supply of electrical power to keep whatever has been written into it. A volatile memory loses its entire contents the instant the supply is withdrawn; a non-volatile memory keeps them indefinitely with the power off. Volatility has nothing to do with how fast a device is, or with how far it sits from the processor — it depends only on the cell technology.
Applying the definition to each memory named in the statements.
Memory | How a bit is held | Needs power to keep it? | Volatile? |
|---|---|---|---|
Read Only Memory (ROM) | A fixed pattern fused or masked into the cell at manufacture; the PROM/EPROM/EEPROM family stores it as trapped charge on a floating gate | No | No — non-volatile |
Random Access Memory (RAM) | Charge on a tiny capacitor that leaks away and must be refreshed (DRAM), or a cross-coupled flip-flop that must stay energised (SRAM) | Yes | Yes — volatile |
Secondary memory (hard disk, SSD, optical disc, flash drive) | Magnetised domains on a platter, trapped charge on a floating gate, or physical pits burned into a disc | No | No — non-volatile |
Reading the three statements against that table.
P asserts that ROM is volatile. A ROM chip is deliberately built so its pattern survives with no supply at all — that is why the boot firmware can be there at all, waiting before any power-on sequence has run. So P is false.
Q asserts that RAM is volatile. Both DRAM and SRAM cells hold a bit only while they are energised, and DRAM additionally needs a periodic refresh; cut the supply and the contents are gone. So Q is true.
R asserts that secondary memory is volatile. Disks, solid-state drives, optical discs and flash sticks are chosen precisely because their contents outlive a power-off — that is the whole point of secondary storage. So R is false.
Cross-check. Exactly one statement survives the definition, and it is the one about RAM, so the choice naming Q alone is what the stem is asking for. A quick sanity check on the same idea: it is precisely because the working copy in RAM is volatile that a machine must copy its data down to a non-volatile secondary store before shutdown, and must reload it from ROM-held firmware and from disk on the next start.