1-5: B*ADAA
6-10: CBAAD
11-15: BACDC
16-20: BDCBD
21-25: CACBA
26-30: CCDDD
31-33: DBA
Explanation
Note:
Q1 may be cancelled due to lack of discriminatory power as the explanation of the location of silver coating is way out of DSE syllabus. Most candidates will simply blind guess.
Q30 D but not B:
Indeed the voltage across the branch with xy included is 6V. However, all the pd of the branch will be taken up by the upper half of resistor which is connected to x, and the xy itself, being the remaining part of the branch, should share no pd.
continue...
14 留言
作者已經移除這則留言。
回覆刪除Q30 could you find another way to explain your answer? The explanation is very confusing
回覆刪除Q30 someone argues that the answer is B as they say that x,y is not connected. Is that true?
回覆刪除Q30 must be B not D. Note that when you connect a voltmeter between XY, no current will pass through the voltmeter and X and Y. Current will only flow through the bottom half of the resistor, the voltage across bottom half of resistor is 6V. No current will flow through the top half of the resistor, so the voltage across the top half of the resistor is 0V. Thus, overall Vxy = 0V + 6V = 6V.
回覆刪除I think so. If zw has a 6V power supply, the voltameter and the power is in parallel. So V(xy) =V(zw) =6V
刪除If the answer is D, you have just won a Nobel prize
回覆刪除I think the answer for question 9 should be B (Not 100% sure though), because from what I understand, the period of 0.2s in which the particle changes its direction of motion should be approximately equal to the period for it to decelerate from 0.5 ms-1 to 0ms-1(instantaneous stop).
回覆刪除Nope. Read the question. It later travels in the same speed in opposite direction. a = [(0.5)-(-0.5)]/0.2
刪除No6 B? The rod has no weight and the wall is smooth
回覆刪除the rod is hinged to the wall
刪除You can try to take moment about the point of the string on rod,then the normal reaction should balance the moment of the load
刪除Q30 why not A?
回覆刪除30 is B arrr
回覆刪除Can you post the MC of 2018 HKDSE physics in dse00?
回覆刪除