The picture below shows a multimeter similar to those used in many school
laboratories.
http://upload.lsforum.net/users/public/w15569^u95.jpg
Which one of the following would be the best setting if you were asked to use
the instrument to measure the current in the 100 Ω resistor in the circuit above?
A 2000 μ
B 20 m
C 200 m
D 10 A
Why the answer is C?
multimeter to measure current
2014-05-07 12:11 am
回答 (1)
2014-05-07 4:48 pm
✔ 最佳答案
用電錶量度電流或電壓值，如你不清楚實際數值有多大，電錶上檔位就要由最大開始，以防燒毁電錶，如實際數值越接近檔位，量度數值就越精準。以上是一般做法，但你問為何要用某一檔位，就要先看你圖值，計算電流用公式i=v/r，3/110=27ma，所以答案是C，至於電壓量度，同樣用公式v=ir，0.027*100=2.7v，所以只有B最接近。
收錄日期: 2021-04-13 22:11:18
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20140506000051KK00112