本题目来源于试卷: Kognity IB Physics A.0 Measurements & Uncertainty，类别为 IB物理学
[单选题]
A student measures two f-nop t/,2s/h/t tnr:0cn fhv lx3h /oefjy ,4 *irf+yyengths as follows: $$a = (10 \pm 0.1) \; cm$$ $$b = (20 \pm 0.1) \; cm$$
Which of the following quantities has the largest percentage uncertainty?
A. $a$
B. $b$
C. $a+b$
D. $a-b$
参考答案: D
本题详细解析:
The largest percentage uncertainty will resud/(hq zhm3a5,c2ugz *dx8rbi;ks9ie lt from the largest absolute uncertainty divided by the smallest measurement value. A and B have an absolute uncertainty of 0.1 cm, while for C & D it is 0.2 cm. So the percentage uncertainties are: A 1(sdxi5z rz/d3qcu 2a igekhmh8,9b;* %; B 0.5%; C 0.67%; and D 2%. Clearly D is the largest.
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