O-level Science (Physics) Suggested Answers for Electromagnetic Spectrum

N05/2/3
(a) ultra-violet radiation [1], radio waves [1]
(b) number of complete waves produced per second [1]
(c) speed of wave = 3.0 × 10^8 m/s [1]
(d) transverse wave OR can travel through a vacuum [1]

N06/2/5a

different frequencies or wavelengths [1]

N08/2/2

(a) infra-red radiation [1]
(b) microwaves [1]
(c) gamma rays [1]

O-level Science (Physics) N09/2/10a

There are two different kettles. The bodies of the kettles are made from different materials. Kettle A is made from shiny silver-coloured metal. Kettle B is made from white plastic. Discuss the suitability of each material in reducing heat losses from the kettles when they are used to boil water.

GCE O-level 5116 Science (Physics) 2009 November Paper 2 Question 10(a)

Answer: Both shiny surfaces (Kettle A) and white surfaces (Kettle B) are poor emitters of thermal radiation and so they help to reduce the thermal energy loss through radiation from the surfaces of the kettles to the surroundings. However, plastic surfaces (Kettle B) are poorer thermal conductors than metal surfaces (Kettle A) and so plastic surfaces are less effective than metal surfaces in transferring thermal energy, which is then lost through radiation, through conduction from the contents of the kettle to the surface of the kettle. Hence, the surface of Kettle B is more suitable in reducing heat loss when it is used to boil water.

O-level Science (Physics) N04/2/4bii

An athlete runs a 100 m race in 12.5 s. Explain why, for part of the race, the athlete must have been running faster than the speed calculated in (a).

GCE O-level 5052 Science (Physics) 2004 November Paper 2 Question 1(b)

Answer: The runner accelerates from rest.

Proof: Consider the area under an arbitrary speed-time graph that starts from rest and the area under another speed-time graph that is travelling at a constant speed, which is equal to the maximum speed of the first graph. Both graphs stop at time t. Thus, the area under the first speed-time graph  = average speed x t while the area under the second speed-time graph = maximum speed x t. Since first area < second area, hence average speed < maximum speed.

O-level Physics N15/2/4bii

Suggest why the hydraulic press does not work properly if the oil contains bubbles of air.

GCE O-level 5059 Physics 2015 November Paper 2 Question 4(b)(i)

1) Inefficient - Work done by piston with effort is more than work done by piston with load (because some work done to compress the gas).

2) Pascal principle - Pressure at piston with effort will not be equal to the pressure at piston with load.

3) Time lag - The piston with load will take some time to move after the effort is being exerted.

Note: Point 2 can be deduced from point 1. And I believe all these points might not be valid when we use the hydraulic press quasi-statically after it has reached dynamic equilibrium (pressure of gas = pressure of surrounding liquid).

NUS PC1431 (AY11/12 SEM 2) FINAL EXAM SUGGESTED SOLUTIONS

I don't have time to draw any nice diagrams so you may have to spend some time reading my long answers. Hopefully, I don't have too many typos. Just leave a comment if you have found one and alert me if you think I am talking rubbish anywhere in the solution. Anyway, the examination paper can be obtained from http://libportal.nus.edu.sg/frontend/index. =)

(Disclaimer: The author has tried his best to ensure the quality of the solution. However, the author will not responsible for any liabilities that arise directly or indirectly from the usage of these solutions.)

NUS PC1432 (AY11/12 SEM 2) FINAL EXAM SUGGESTED SOLUTIONS

I don't have time to draw any nice diagrams so you may have to spend some time reading my long answers. Hopefully, I don't have too many typos. Just leave a comment if you have found one and alert me if you think I am talking rubbish anywhere in the solution. Anyway, the examination paper can be obtained from http://libportal.nus.edu.sg/frontend/index. =)

(Disclaimer: The author has tried his best to ensure the quality of the solution. However, the author will not responsible for any liabilities that arise directly or indirectly from the usage of these solutions.)

Part I Question 5: http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/michel.html.

Arriving at the relationship between the electric field and the surface charge density: http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elesht.html. A more rigorous way of arriving at the magnitude of the attractive force: http://www.schoolphysics.co.uk (Example 9.4).

Part II Question 8(a): Several variants of the question: http://www.ece.ucdavis.edu/~lxgliu/eec130a/2012winter/hw9s.pdf (see Problem 5.40).

Part II Question 9(d): http://panda.unm.edu (see bottom of Page 4)

NUS PC1432 (AY12/13 SEM 1) FINAL EXAM SUGGESTED SOLUTIONS

I don't have time to draw any nice diagrams so you may have to spend some time reading my long answers. Hopefully, I don't have too many typos. Just leave a comment if you have found one and alert me if you think I am talking rubbish anywhere in the solution. Anyway, the examination paper can be obtained from http://libportal.nus.edu.sg/frontend/index. =)

(Disclaimer: The author has tried his best to ensure the quality of the solution. However, the author will not responsible for any liabilities that arise directly or indirectly from the usage of these solutions.)

Part II Question 7: This question is similar to Question 3 of AY10/11. Here's the solution for this problem: http://teacher.pas.rochester.edu (Problem 31.15). The graph should look something like this: http://www.ittc.ku.edu (last page).

NUS PC1432 (AY10/11 SEM 1) FINAL EXAM SOLUTIONS

The solutions can be found here: http://www.nusdiary.com/groups/nussolutions/forum/topic/pc1432-sample-lab-reports-tutorials-midterms-and-final-exams-solutions/.

NUS PC1431 (AY11/12 SEM 1) FINAL EXAM SUGGESTED SOLUTIONS

I don't have time to draw any nice diagrams so you may have to spend some time reading my long answers. Hopefully, I don't have too many typos. Just leave a comment if you have found one and alert me if you think I am talking rubbish anywhere in the solution. Anyway, the examination paper can be obtained from http://libportal.nus.edu.sg/frontend/index. =)

(Disclaimer: The author has tried his best to ensure the quality of the solution. However, the author will not responsible for any liabilities that arise directly or indirectly from the usage of these solutions.)

NUS PC1432 (AY10/11 SEM 2) FINAL EXAM SUGGESTED SOLUTIONS

I don't have time to draw any nice diagrams so you may have to spend some time reading my long answers. Hopefully, I don't have too many typos. Just leave a comment if you have found one or if you think I am talking rubbish anywhere in the solution. Anyway, the examination paper can be obtained from http://libportal.nus.edu.sg/frontend/index. =)

(Disclaimer: The author has tried his best to ensure the quality of the solution. However, the author will not responsible for any liabilities that arise directly or indirectly from the usage of these solutions.)

* Part I Question 5,6,and Part II Question 9 are just some boring A-level physics questions. =) I shall spend my precious time other tougher questions. Having said that, I may still come back to Question 9 as Quantum Physics is my interest.

NUS PC1432 (AY09/10 SEM 2) FINAL EXAM SUGGESTED SOLUTIONS

*The suggested solutions for PC1432 (AY12/13 SEM 1) can be found here: http://jatw88.blogspot.sg/2013/04/nus-pc1432-ay1112-sem-2-final-exam.html. The ones for AY11/12 SEM 2 can be found here: http://jatw88.blogspot.sg/2013/04/nus-pc1432-ay1112-sem-2-final-exam_30.html.

Currently, I don't have time to draw any nice diagrams so you may have to spend some time reading my long answers. Hopefully, I don't have too many typos. Just leave a comment if you have found one or if you think I am talking rubbish anywhere in the solution. Anyway, the examination paper can be obtained from http://libportal.nus.edu.sg/frontend/index. =)

DISCLAIMER: THE AUTHOR HAS TRIED HIS BEST TO ENSURE THE QUALITY OF THE SOLUTION. HOWEVER, THE AUTHOR IS NOT RESPONSIBLE FOR ANY LIABILITIES THAT ARISES DUE TO QUALITY OF THE SOLUTION.

PART II QUESTION 7(b): This is a tough question which commonly appears in examinations and PhD qualifying examinations. The solutions can be found from the following http://prezi.com/41twyc0vdsam/pc2131-tutorial-2/ (go to question 4). These slides belong to a TA of NUS physics department. I will give a more detailed answer if I have time.

PC3231 (AY10/11 SEM 1) FINAL EXAMINATION SUGGESTED SOLUTION

I have volunteered to come out with the suggested solutions for PC3231's final examination questions. Since it's my work, so I decided to share with you all. The examination paper can be obtained from http://libportal.nus.edu.sg/frontend/index.

(Disclaimer: The author has tried his best to ensure the quality of the solution. However, the author will not responsible for any liabilities that arise directly or indirectly from the usage of these solutions.)