Monday, November 29, 2010

SPM tips ~ paper 2 ( light )

Diagram 9.1 and Diagram 9.2 show light rays from two identical objects passing through two identical convex lenses. Both lenses produce real images. F is the focal point for the lens.
Rajah 9.1 dan Rajah 9.2 menunjukkan sinar cahaya dari dua objek yang serupa melalui dua kanta yang serupa. Kedua-dua kanta tersebut menghasilkan imej nyata. F adalah titik fokus untuk kanta tersebut.


(a)
(i)
Name the phenomenon involved. [1 mark]
Namakan fenomena yang terlibat. [1 markah]


Hits for solving the problem :
Refraction of light is the bending of light ray at the boundary as it travels from one medium to another.
Reflection of light occurs when the light ray strike the surface of mirror.

ii)
Observe Diagram 9.1 and Diagram 9.2. Compare the object distance, the image distance, the size of the image and the power of the lens. Relate the size of the image with the object distance. [5 marks]

Perhatikan Rajah 9.1 dan Rajah 9.2. Bandingkan jarak objek, jarak imej, saiz imej dan kuasa kanta. Hubungkaitkan saiz imej dengan jarak objek. [5 markah]

Hits for solving the problem :
  • Pay attention to the marks allocated. the marks usually indicates the number of points required.
  • Understand the task
  1. Compare the object distance,
  2. Compare the image distance,
  3. Compare the size of the image
  4. Compare the power of the lens.
  5. Relate the size of the image with the object distance.

(b)
Diagram 9.3 shows the structure of a simple camera.
Rajah 9.3 menunjukkan struktur sebuah kamera ringkas.


(i)
Explain how the camera is able to capture the image of a distant object. [3 marks]
Terangkan bagaimana kamera boleh merakam imej suatu objek jauh. [3 markah]

Hits for solving the problem :
  • Pay attention to the marks allocated , the marks usually indicates the number of points required

(ii)
State the range of the object distance where the image formed is sharp. [1 mark]
Nyatakan julat jarak objek bagi kedudukan imej yang tajam. [1markah]

(c)
A student is given two convex lenses, R and S. The focal length for R and S are 20 cm and 5 cm respectively. Suggest and explain how to build a microscope which produces a sharp and magnified image based on the following aspects:

Seorang pelajar diberi dua kanta cembung R dan S. Panjang fokus untuk R dan S adalah 20 cm dan 5 cm masing-masing. Cadang dan terangkan bagaimana anda membina sebuah mikroskop yang menghasilkan imej yang tajam dan dibesarkan berdasarkan aspek-aspek berikut:

Hits for solving the problem :
Underline the important information given in the question, such as focal length for each lens, build a microscope...

(i)
Arrangement of lenses
Susunan kanta

(ii)
Position of object
Kedudukan objek

(iii)
Position of the first image
Kedudukan imej pertama

(iv)
Distance between the two lenses
Jarak antara kedua-dua kanta

(d)
Suggest two modifications that need to be done to the microscope to produce a bigger final image. [2 marks]

Cadangkan dua ubahsuaian yang perlu dibuat pada mikroskop untuk menghasilkan imej akhir yang besar .[2 markah]

Hits for solving the problem :
M= Mo x Me

Sunday, November 28, 2010

SPM Trial MARA 2010 ~ paper 2 ( waves )


Diagram 8.1 shows Aini trying to open the house’s front gate using a remote control. Even though Amin is blocking her, the gate can still be opened.
Rajah 8.1 menunjukkan Aini cuba membuka pintu pagar rumah dengan menggunakan alat kawalan jauh. Walaupun Amin menghalangnya pintu pagar masih boleh dibuka.
(a)
(i)
Name the wave phenomenon involved
Namakan fenomena gelombang yang terlibat.

ii)
On Diagram 8.2, draw the wave pattern based on the situation in Diagram 8.1.

(b)
Table 8.1 shows the characteristics of three waves, X, Y and Z to be used in the remote control for the gate. Calculate the wavelength of each wave.
Jadual 8.1 menunjukkan ciri-ciri untuk tiga gelombang, X, Y dan Z yang akan digunakan dalam alat kawalan jauh bagi pintu pagar. Hitungkan panjang gelombang bagi setiap gelombang.

(i)
Wave X
Gelombang X

(ii)
Wave Y
Gelombang Y

(iii)
Wave Z
Gelombang Z

(c)
(i)
Based on your answers in 8(b), which wave is the most suitable to be used in the remote control for the gate?
Berdasarkan jawapan anda di 8(b), gelombang manakah yang paling sesuai digunakan untuk alat kawalan jauh bagi pintu pagar itu?


(ii)
State one reason for the answer in 8(c)(i).
Nyatakan satu sebab bagi jawapan 8(c)(i).

(d)
Based on the values of the wave speed shown in Table 8.1,
Berdasarkan nilai laju gelombang dalam udara yang ditunjukkan dalam Jadual 8.1,

(i)
Predict what wave X is.
Ramalkan gelombang X.

(ii)
State one application for wave X.
Nyatakan satu kegunaan gelombang X.

Suggested answer:

a)
i)
Diffraction of waves
ii)


b)

i) Velocity = Frequency × Wavelength
3.3 x 10 2 = 4. 0 x 105 x wavelength
wavelength = 8.25 x 10
-3 m

ii) wavelength = 0.75m

iii) wavelength = 7.5 x 1o -11

c)
i) wave Y

ii) The e of effect diffraction is very obvious.

d)

i) Sound wave

ii)Disintegration of kidney stones // Locating an object under water // remove plaque from teeth

Saturday, November 27, 2010

SPM Trial MARA 2010 ~ paper 2 ( Resistance )


Diagram 6.1 and Diagram 6.2 show two electric circuits each consisting of a copper wire.
Rajah 6.1 dan Rajah 6.2 menunjukkan dua litar elektrik masing-masing mengandungi seutas wayar kuprum.

(a)
Name the quantity measured by the ammeter.
Namakan kuantiti yang diukur oleh ammeter.

Hits for answer the problem :
Key words " quantity"


(b)
(i) Compare the thickness of the copper wire in Diagram 6.1 and Diagram 6.2.
Bandingkan ketebalan wayar kuprum dalam Rajah 6.1 dan Rajah 6.2.
(ii)
Compare the ammeter reading in Diagram 6.1 and Diagram 6.2.
Bandingkan bacaan ammeter dalam Rajah 6.1 dan Rajah 6.2.

(iii) Relate the thickness of the copper wire to the ammeter reading.
Hubungkaitkan ketebalan wayar kuprum dengan bacaan ammeter .

(iv)
Relate the thickness of the copper wire to its resistance.
Hubungkaitkan ketebalan wayar kuprum dengan rintangan.


(c)
You are provided with three light bulbs labelled A, B and C labelled A, B and C as shown in
Diagram 6.3.
Anda dibekalkan dengan tiga mentol Anda dibekalkan dengan tiga mentol berlabel A, B dan C seperti dalam Rajah 6.3. seperti dalam Rajah 6.3.
Draw and label an electric circuit connecting all the three bulbs in which all the bulbs should light up with normal brightness connected to a power supply of 240 V alternating current . Add switches to the circuit.
Lukis dan label satu litar elektrik yang menyambungkan ketiga-tiga mentol di mana semua a mentol seharusnya menyala dengan kecerahan normal apabila disambungkan kepada bekalan kuasa 240 V arus ulang-alik. Tambahkan suis pada litar anda.



Suggested answers:

a) Electric current

b)
i) Thickenss of the copper wire of diagram 6.2 thicker than diagram 6.1.

ii) Ammeter reading in diagram 6.1 is less than diagram 6.2.


iii) The thicker the copper wire, the higher the ammeter reading.


iv) The thicker the copper wire, the lower the resistance.

c)



Friday, November 26, 2010

SPM Trial MARA 2010 ~ paper 2 ( Thermal Equilibrium )

Question 5

A student carries out an activity to record the temperature change of oil and water. Both liquids are heated by identical heaters for two minutes. The initial temperature of oil and water are 30oC.
Seorang pelajar membuat aktiviti untuk merekod perubahan suhu minyak dan air. Kedua cecair dipanaskan oleh pemanas yang serupa selama dua minit. Suhu awal minyak dan air adalah 30oC.


(a) Name the condition in which the temperature of the water is equal to the temperature of the thermometer.
Namakan keadaan di mana suhu air adalah sama dengan suhu termometer.

Hits for answer the problem :
Key words " temperature of the water is equal to the temperature of the thermometer.
"

(b)
Observe Diagram 5.1 and Diagram 5.2. Compare,
Perhatikan Rajah 5।. dan Rajah(b) 5 .2. Bandingkan

(i) the mass of oil and mass of water.
jisim minyak dan jisim air.

Hits for answer the problem :
Observe the compression balance indicator //scale.

(ii) the temperature change in oil and also in water.
perubahan suhu minyak dan suhu air.

Hits for answer the problem :
Observe the thermometer .

(c)
(i) Compare the amount of heat supplied by the heater to the oil and to the water.
Bandingkan jumlah haba yang dibekalkan oleh pemanas kepada minyak dan kepada air.

Hits for answer the problem :
key words "Both liquids are heated by identical heaters for two minutes"

(ii) Compare the amount of heat absorbed by oil and water.
Bandingkan jumlah tenaga yang diserap oleh minyak dan air.

Hits for answer the problem :
Assuming that no heat lost to the surroundings,
heat received by liquids = heat given out by the heater.

Q=mcӨ = Pt


(iii) Name the physical quantity that will explain the comparison you made in 5(b)(ii).
Namakan kuantiti fizik yang menerangkan perbandingan yang dibuat dalam 5(b)(ii).

(d)
If the heating time is increased to 5 minutes, will there be any change in the physical quantity in (c)(iii)? Explain your answer.
Jika tempoh pemanasan ditambah kepada 5 minit, adakah sebarang perubahan pada kuantiti fizikal pada (c)(iii)? Terangkan jawapan anda


Suggested answers:

a) Thermal Equilibrium

b)
i)Mass of the oil and water are same .
ii)Temperature of oil is higher than temperature of water

c)
i) Heat supplied by the heater to the oil is equal to heat supplied to the water
ii) The amount of heat absorbed by oil and water are same .
iii) Specific heat capacity

d)
When two objects of equal masses are heated at equal rates, the object with the smaller heat capacity will have a faster temperature increase.

The specific heat capacity of oil is smaller than water, therefore oil show higher temperature.

Wednesday, November 17, 2010

SPM Trial MARA 2010 ~ paper 2 ( Impulsive force )

Question 2
Diagram 2 shows a baseball player wearing a soft thick glove to catch a ball during a baseball match.
Rajah 2 menunjukkan seorang pemain bola lisut memakai sarung tangan tebal yang lembut untuk menangkap bola semasa pertndingan bola lisut.


(a) What is meant by impulsive force?
Apakah maksud daya impuls?

(b) The ball of mass 0.15 kg moves with a velocity of 20 m s when it is hit.
Calculate the impulsive force acting on the glove when the time of impact is 8.0 x 10 -2 s.

Bola berjisim 0.15 kg bergerak dengan kelajuan 20 m s apabila dipukul.
Hitungkan daya impuls yang bertindak ke atas sarung tangan jika masa tindakbalas 8.0 x 10 -2 s.


(c) Compare the impulsive force if the baseball player wears a hard glove to catch the ball. Explain your answer.
Bandingkan daya impuls yang di hasilkan jika pemain itu menggunakan sarung tangan yang keras untuk menangkap bola. Jelaskan jawapan anda.

Hits for answer the problem :
Decreasing the time of impact will increase the magnitude of the impulsive force, and vice versa.

Suggested answers:

a)
Impulsive force is defined as the rate of change of momentum in a collision or explosion.

b)


c) A larger impulsive force is produced if the baseball player wears a hard glove. Because the time interval of interaction is small.

Tuesday, November 16, 2010

SPM Trial MARA 2010 ~ paper 2 ( Water tank )


Question 7

Diagram 7 shows a public water tank which supplies water for domestic use to a residential area.
Rajah 7 menunjukkan sebuah tangki air awam yang membekalkan air untuk kegunaan domestik di satu kawasan perumahan.

(a)
State one factor which affects pressure in a liquid.
Nyatakan satu faktor yang mempengaruhi tekanan dalam cecair.
Hits for solving problem :
Liquid pressure increase with depth//height, and increase with density.
(b)
Based on Diagram 7, calculate the water pressure at X.
(Density of water = 103 kg m-3).
Berdasarkan Rajah 7, hitungkan tekanan air di X.
( Ketumpatan air =103 kg m-3).
Hits for solving the problem:
~ list all info given or underline the importance information given.
Given ρ, g ,h and find P .
~ state the formula, P = ρ g h
~ substitute the value for each quantity
~ answer with the correct unit.

(c)
Tenants on the fifth floor of the apartment block are unable to obtain tap
water. Why?
Penghuni di tingkat lima blok pangsapuri tidak menerima bekalan air paip. Mengapa?

(d)
Suggest and explain modifications to the water distribution system shown in Diagram 7, to ensure the following :
Tangki air itu tidak dapat memenuhi keperluan semua penghuni di blok pangsapuri lima tingkat. Cadang dan terangkan pengubahsuaian yang perlu dilakukan untuk setiap yang berikut:

(i)
Sufficient water supply for all area residents.
Bekalan air yang mencukupi untuk semua penghuni kawasan.


(ii)
Water supply reaches the fifth floor of the apartment building.
Bekalan air boleh sampai ke tingkat lima blok pangsapuri.

e)
The public water supply system often faces a problem in delivering water to water tanks located on tall buildings.
Suggest and explain one other way to overcome this problem.
Sistem bekalan air awam kerapkali menghadapi masalah untuk menyalurkan air ke tangki
air yang berada di bahagian atas bangunan tinggi.
Cadangkan dan jelaskan satu cara lain untuk mengatasi masalah ini.
Hits for solving problem (c) - (e):
In prublic water supply system, the water is pumped up to a water tank located higher than the building in that area.
Due to the gravitational pull, water in the storage tank is maintaned at a high pressure and enables water to flow to the lower area ( consumers )
Suggested answers:

a) The height of water tank.
b)
P = ρ g h
= 1000 x 10 x 10
= 100 000 N/ m
= 100 000 Pa

c)
Water tanks are tall to provide pressure.
The location of fifth floor apartment is exceed the height that the tank's water pressure can handle.

d)
i) Build a larger water tank,to holds enough water for all area residents.
ii) Ensure water tank located higher than apartment , to provide the necessary pressure.

e) Install a pump to provide pressure.


Monday, November 15, 2010

SPM Trial MARA 2010 ~ paper 2 ( CRO )

Question 4

A cathode ray oscilloscope ( C. R. O) is an instrument that converts electronic and electric signals to a visual display.

Diagram 4.1 shows the structure of a simple cathode ray oscilloscope (CRO).
Rajah 4.1 menunjukkan struktur satu osiloskop sinar katod ringkas (OSK) .


(a) (i) Based on Diagram 4.1, name the component T.
Berdasarkan Rajah 4.1, namakan komponen T.

Hints for solving the problem (ii) and (iii) :
The process of emission of electrons from the surface of a heated metal is known as thermionic emission.


This is because some of the electrons have gained enough kinetic energy to break free from the metal surface and escape to the surroundings.

(ii) Explain what happens to the electrons on the surface of T when T is heated.

Terangkan apa yang berlaku kepada elektron pada permukaan T jika T dipanaskan.

(iii) Name the physics process in (a)(ii).
Namakan proses fizik yang berlaku dalam (a)(ii).

(b) A student uses a CRO to study the output voltage of a bicycle dynamo. The time-base is set at 100 ms/division and the Y gain control is set at 0.5 V/division.

Seorang pelajar menggunakan OSK untuk mengkaji voltan output yang dijana oleh sebuah dinamo basikal. Dasar masa telah dilaraskan pada 100 ms/bahagian dan gandaan Y dilaraskan pada 0.5 V /bahagian.


Hits for solving the problem:



(i) Calculate the frequency of the wave produced by the bicycle dynamo.
Hitungkan frekuensi gelombang yang dihasilkan oleh dinamo basikal.

Hits for solving the problem:
f = 1/ T

(ii) On Diagram 4.2, draw a new trace to show the voltage output if the frequency of the dynamo is doubled.

Pada Rajah 4.2, lukiskan surihan yang baru untuk menunjukkan voltan output jika frekuensi dinamo digandakan.



Suggested answers:

a)

(i) Cathode

(ii)Cathode or T emits electrons when it is heated.

(iii) Thermionic emission

b)

(i) time taken to complete one oscillation , T = 4 x 100 ms

T= 400 ms

Frequency , f = 1 / T

f = 1/ 400 ms

f = 2.5 Hz

(ii)




Sunday, November 14, 2010

Tips for Physics Paper 1 and paper 2

Paper 1


1. Cancel or mark (x) which is wrong option then choose.


2. Always refer the formula given on formula list.

( one step calculation only because 1 question = 1 mark)


3. Blacken each finished answer immediately.


Paper 2


1. Definition of the term in Physics. ( please refer to text book)

Force, work, power, momentum, inertia, impulsive force, coherent, pressure, temperature and heat...


2. The principle in Physics and application.

Force in equilibrium, thermal equilibrium, Pascal's principle, conservation of momentum.


3. The Law in Physics and application.

Hooke's Law, Ohm's Law, Charles Law, Boyle's Law, Newton"t first law, Newton Second Law...


4. Drawing skills ( Use pencil, ruler and other suitable drawing tools)

Total internal reflection, ray diagram, interference , field circuit, refraction of wave, circuit...


5. Graph skills

Axis, plotting, scale, straight or curve line, gradient , extrapolation.


Thursday, November 11, 2010

Decision Making - - Hydraulic jack

Diagram shows a hydraulic jack in a car service centre.





Table below shows four type of hydraulic oil, K, L, M and N , with different specifications. You are required to determine the most suitable hydraulic oil to run the hydraulic jack.

Study the specifications of all four types of hydraulic oil from the following aspects:

i ) Boiling point of the hydraulic oil

ii) Specific heat capacity of the hydraulic oil

iii) Density of hydraulic oil

iv) Rate of vaporisation of hydraulic oil

Suggested answer:

i) Has high boiling point
~ so that hydraulic fluid not easily boiling

ii) Has higher specific heat capacity
~ so that it can't be easily became hot

iii) Has lower density
~ so the hydraulic oil is not heavy

iv) Has lower rate of vaporisation
~ Volume of the hydraulic oil not easily vaporise.

Hydraulic oil L is chosen

Reason :
L has high boiling point, higher specific heat capacity, lower density and lower rate of vaporisation .


Tuesday, November 9, 2010

Structure question -( concave mirror)

Percubaan SPM MRSM 2010


Diagram 1 shows an object placed in front of a mirror.
Rajah 1 menunjukkan satu objek diletakkan di hadapan sebuah cermin.
(a) Name the type of mirror shown in Diagram 1.
Namakan jenis kanta yang digunakan dalam Rajah 1.

Hints for solving the problem :
A convex mirror curves outwards.
A concave mirror curves inwards.
(b) Draw the image in the box given in Diagram 1.
Lukiskan imej dalam petak yang disediakan pada Rajah 1.

Hints for solving the problem :
Draw the image with its tail on the axis. The head is where the two reflected rays meet.
convex mirror typically make a virtual image.
A virtual image is shown using a dotted line.

(c) Based on Diagram 1, tick the correct statement about the image formed.
Berdasarkan Rajah 1. tandakan pada pernyataan yang betul mengenai imej yang terbentuk.

[] The image can be formed on a screen.
[] Imej boleh terbentuk pada skrin.
[] The image cannot be formed on a screen.
[] Imej tidak boleh terbentuk pada skrin.

Hints for solving the problem :
Real image can be displaced on a screen.
Virtual image can be seen by the observer but not be displaced on a screen.

(d) What happens to the size of the image if the object is placed at X?
Apakah yang terjadi pada saiz imej jika objek diletakkan pula di X ?
Hints for solving the problem :
The image appears larges in size when the object is nearer to the convex mirror.

Suggested answers:

(a) Convex mirror
(b)
(c)The image cannot be formed on a screen.
(d) Image is smaller than original size

Monday, November 1, 2010

Happy Deepavali