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 tofrhhp6 e 1t+88+j4;r sm5bisl8xrfq;p fd39 yoky k8wo lengths 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 result from the largest absolute unc/k ahma 8q,5tep7na e)ertainty divided by the smallest /aqemn5k8e7pat), h ameasurement 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%; B 0.5%; C 0.67%; and D 2%. Clearly D is the largest.
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