問89
頻出度★★☆
情報の表現方法に関する次の記述中の a～c に入れる字句の組合せはどれか。 情報を, 連続する可変な物理量 (長さ, 角度, 電圧など) で表したものを [ a ] データといい, 離散的な数値で表したものを [ b ] データという。 音楽や楽曲などの配布に利用される CD は, 情報を [ c ] データとして格納する光ディスク媒体の一つである。
令和3年度 ITパスポート試験 問89
テクノロジ系基礎理論 › 情報に関する理論
This question's explanation and your answers so far.
解説
問 89
Incorrectア
a=analog and b=digital are correct, but c=analog is wrong. A CD is an optical disc that stores music information as a sequence of numbers obtained by sampling and quantizing it, that is, as digital data; c is not analog.
- イ
正解 The correct answer is イ (a=analog, b=digital, c=digital). Item a is “information represented by continuous, variable physical quantities (length, angle, voltage, etc.)”, so it is “analog” data whose values change continuously without breaks. Item b is “information represented by discrete numerical values”, so it is “digital” data expressed as separate, discrete numbers (such as 0/1). The CD in item c is an optical disc medium that records “digital” data obtained by sampling a continuous music waveform at fixed intervals and quantizing it into a sequence of numbers, so c is also digital. Only イ satisfies all three of these.
Incorrectウ
a=digital and b=analog are reversed, which is wrong. Item a, represented by continuous variable physical quantities, is analog, and item b, represented by discrete numerical values, is digital; the two assignments have been swapped. It also lists c as analog, which is likewise wrong.
Incorrectエ
c=digital is correct, but a=digital and b=analog are reversed, which is wrong. Item a, a continuous quantity, must be analog, and item b, discrete numerical values, must be digital; the assignments for a and b have been swapped.
ここがポイント
- The distinction between the basic definitions: analog means representing information with continuously changing physical quantities (length, angle, voltage, etc.), while digital means representing it with discrete numerical values (separate values such as 0/1).
- Optical discs such as CDs are media that record “digital data”, which is produced by sampling and quantizing a sound's continuous waveform into numerical values.
用語