問56
頻出度★★☆
PC において, 電力供給を断つと記憶内容が失われるメモリ又は記憶媒体はどれか。
令和6年度 ITパスポート試験 問56
テクノロジ系コンピュータ構成要素 › メモリ
This question's explanation and your answers so far.
解説
問 56
Incorrectア
DVD-RAM is an optical disc (storage medium) that holds information as physical or chemical state changes on its recording surface. It is a non-volatile medium whose data remains regardless of power, so it does not fit “lost when the power is cut off.”
- イ
正解 The correct answer is “イ DRAM.” A memory whose stored contents are lost when the power supply is cut off is called “volatile memory.” DRAM (Dynamic RAM) is a semiconductor memory that holds information by storing electric charge in capacitors, and it is used as a PC’s main memory. Because the charge naturally discharges over time, periodic refresh (rewriting) is required even while powered, and once the power is cut off the charge disappears and all stored contents are lost. This is exactly the property of being “volatile,” and it matches the memory asked about in the question, which “loses its stored contents when the power supply is cut off.”
Incorrectウ
ROM (Read Only Memory) is a representative non-volatile memory that retains its contents even when the power is turned off. Because it is used to store programs needed from the moment of power-on, such as the BIOS, it must not be volatile, so it does not meet the condition of the question.
Incorrectエ
Flash memory is a non-volatile memory used in USB drives, SSDs, and SD cards, and it retains data even when the power is turned off. It does not have the property of losing its contents when power is cut off, so it is incorrect.
ここがポイント
- Volatile memory (contents disappear when the power is turned off) = the RAM family; the representative is DRAM, used as main memory. On the other hand, ROM, flash memory, and optical discs (such as DVD-RAM) are non-volatile and retain their contents even when the power is turned off.
- DRAM holds charge in capacitors so it needs refreshing; when power is lost the charge disappears and the stored contents are lost, which is the essence of being “volatile.”
用語