Kognity IB Physics A.0 Measurements & Uncertainty (id: 3dae35a97)

admin

本题目来源于试卷: Kognity IB Physics A.0 Measurements & Uncertainty，类别为 IBDP Physics

[单选题]
A student measures ttht)l (lo(fn/ wo lengths as f3d 7,py0 cevd5yun: khollows: $$a = (10 \pm 0.1) \; cm$$ $$b = (20 \pm 0.1) \; cm$$
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 -qq: r y3w(r(jt;pwxvt-gy oxsq0-:babsolute 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%; B 0.5%; b (o(y-yvsr w-qq3- ;t wxqt:px:jrg0 C 0.67%; and D 2%. Clearly D is the largest.