Physics SPM 2013 Paper 1 Answers

The difficulty of the physics paper can be categorized as average to easy. 

There are a few questions which caught my students and teachers attention:
Q30. This question about telescope is quite challenging, students must be very clear of the characteristics of the telescope to be able to answer this question. Good question. 

Q32. This questions is about water waves from sea to shore. Students can easily make mistake for this question. But with the help of the diagram and clear understanding of the concept most students can answer its correctly. 

Q43. The best answer is D, although the answer given in D is not accurate. A full rectifier should have a smoother output and a more horizontal flat line. The answer D looks more like a halfwave rectification than a full wave rectification. 

Q48. The question is not very clear which will lead to many interpretation of the questions objective. But i believe the setter wants to ask is after 15 minutes, 25% of Gallium of undecayed are left. So i choose the best answer as D. 

Please do share and comment below what you think? 

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30 comments:

  1. A lot of wrong answer given

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  2. 48 I think it should be A. 25% of the atoms have decayed in 15 minutes, so 50% of the atoms will decay in 30 minutes(which is the half-life).

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    Replies
    1. I am totally agree with you!!

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    2. yes agree too should be A

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  3. huh ?? r u sure the answers are correct ??

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  4. Sir,a lot of wrong answer given....could you correct it? Thank u...

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  5. noted with the mistakes. will update it tomorrow. TQ

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  6. tq mr sai mun ... sharing is caring

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  7. Answers updated. something wrong with the numbering :)

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  8. Can i ask the question 32and 48, its correct?

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  9. sir,why Q45 is B,not A

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  10. 48 should be A.. cause 25% have been decayed, not 25% is left..

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  11. The answer for question 45 should be A

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  12. Yes the answer for number 45 should be A, and 48 is A

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  13. Q48 At the end of 30 minutes, only 7/16 [=(1/4) + (1/4)(3/4)] of the radioactive substance has decayed. It takes another 6 minutes+ to decay a further 1/16 to reach half-life. Half-life = 36.7 minutes. Therefore, Q48 has no acceptable answers. Answer for Q45 shd be A

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  14. q48 there is no symbol for capasitor right ?

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  15. Q50 isnt the ans c

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    Replies
    1. why b not c? hope u do reply.

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    2. if sample R(C) is used then the pipes will be covered by high quantity of ionising particle for it have a very long half-life..so it is suitable to use Q(B) for it have a short half life and less covered with ionising particles..

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  16. mr sai mun, please correct the aswer....

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    Replies
    1. which questions and answers you are doubtful of? :)

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  17. mr sai mun, can i know the explanation for Q 50 as well because i thought the ans should be C instead of B ? Is there a correction to that?

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  18. question 45 should be A.It basic concept of n-p-n transistor that the arrow point downward.

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  19. q.49 isn't the answer is D???

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    1. Q 49, the answer is C because:

      No. of neutrons
      = No. nucleons (i.e. neutrons + protons) - No. of protons
      = (226 + 4) nucleons - (88 + 2) protons
      = 230 nucleons - 90 protons
      = 140 neutrons

      Therefore, answer is C (90 protons and 140 neutrons)

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  20. Physics SPM 2013 Paper 1 Answers :
    1A,2A,3A,4B,5C,6B,7C,8B,9D,10B,11A,12D,13C,14A,15D,16C,17C,18C,19A,20B,21A,22C,23A,24B,25C,26A,27A,28A,29D,30C,31C,32B,33D,34B,35B,36B,37A,38C,39C,40A,41D,42B,43D,44A,45A,46D,47B,48A,49C,50B.

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    1. Q 30, the answer is D.

      More than twice before, 'telescope at normal adjustment' were tested in SPM:

      * 2005 P2 Q11(a)(iii) - diagram @ pg. 387 of P-Yr Papers 2005 -2012 ] - D

      * 2006 P2 Q9(c)(i) - diagram @ pg. 393 of P-Yr Papers 2005 -2012] - D

      * Pg 299 of Oxford-Fajar (2013 Ed.) Fig. 5.67 for telescope - D !
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      Q 32, the answer is also D. Reason:

      As water waves enter shallower region (at headland first, then only the bay), its speed slows down with the shortening of its wavelength (again at headland first, then only the bay) without any change in its wave frequency - this is due to refraction of water waves. Which is also why the diagram clearly shows the wavelength (distance between successive wavefronts) at the bay is longer than that at the headland.

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      Q 48, has no answer. Reason:

      Already given in one of earlier comments.

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