問49
頻出度★☆☆
プリンタが1分間に印刷できるページ数を表す単位はどれか。
平成26年度 秋期 ITパスポート試験 問49
This question's explanation and your answers so far.
解説
問 49
Incorrectア
cpi is “characters per inch”, the number of characters that can be printed within one inch. It is an indicator related to character size and character pitch, not the number of pages printed per unit of time (speed), so it is wrong.
Incorrectイ
dpi is “dots per inch”, the number of dots within one inch, and is a unit of resolution. It indicates how fine a printer or scanner prints or scans (image quality), not printing speed, so it is wrong.
- ウ
正解 The correct answer is ウ, ppm. ppm is short for “pages per minute” and expresses the number of pages a printer can print in one minute, that is, its printing speed. The larger the value, the faster the printing; business laser printers are often specified as something like several tens of ppm in monochrome. The definition given in the question, “the number of pages that can be printed in one minute”, is exactly the definition of ppm, so ウ is correct.
Incorrectエ
rpm is “revolutions per minute”, the number of rotations per minute. It is used for things like hard disk rotation speed (for example 7,200 rpm), not as a unit for the number of pages a printer prints, so it is wrong.
ここがポイント
- ppm = pages per minute. The unit that expresses a printer’s printing speed (pages printed per minute).
- Distinguishing confusing units: dpi is resolution (dots per inch), cpi is characters per inch, and rpm is revolutions per minute. Tell them apart by checking what is counted before and after “per”.
用語