点击以下链接 查看O水准其他科目答案.
English Paper 2
E Math Paper 1 E Math Paper 2
A Math Paper 1 A Math Paper 2
Pure Physics Paper 1 Pure Physics Paper 2
Pure Chemistry Paper 1 Pure Chemistry Paper 2
Combined Chemistry Paper 1 (MCQ) Combined Science Paper 2 (Physics) Combined Science Paper 3 (Chemistry)
Reserved for explanations.
[Q23]
In the above diagrams, the orange colored rays indicate the orginal direction of light. Compare the orange colored rays with the refracted rays on the right, you will notice that only in A, light beams become more converging.
这个题目其实稍稍有一点超纲. 不过, 从converging lens这个名称上, 应该可以判断出来”光透过这种透镜后, 会变得更加汇聚”.
For further understanding (this explains why a lens of convex surfaces (凸面) is always a converging lens):
Note: every time when refraction occurs on the intermedia surface, incident angle/refracted angle in the glass will be smaller than the refracted/incident angle in air.
Following this law, you can also explan using graph, why diverging lenses always have concaved surfaces (凹面).
[Q33]
Question: A person touches the live wire. Will it cause the 3A fuse to blow?
Answer: No.
Explanation:The resistance of a human body ranges from a few hundred ohms (wet condition) to a few hundred kilo-ohms (dry condition). So the current will be less than 3A. The fuse will not blow.
Refer to the following table: you will notice that a current that causes death is actually quite small, only 0.1~0.3A
Current
Effect1mA
Threshold – no pain below this point
5mA
A frightening but harmless shock
10 -20mA
Uncontrolled muscular contractions
Loss of muscle control – you cannot let go
50mA
Pain and exhaustion; breathing affected
100 – 300mA
Uncoordinated contraction of the heart leading to death
Q33 起了很多议论。
有 B/C 的答案 x.x
我也是搞不清楚。。
见2楼详解.