spm 4531 2006 physics p2 berjawapan

8/2/2019 Spm 4531 2006 Physics p2 Berjawapan

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Paper 2 0nlg Time: 2 hours and B0 minutesSection A[60 marksl

Answer all questions in this section.You are a.duisedto spend g0 minutes on this section.1 Diagram 1.1 shows an electric circuit.

Diagram 1.1(a) (i) Name instrument e.

IL mark](ii) What is the function of R in the circuit?

(b) Diagram 1.2 shows two t;rpes of ammeters, X and yDiagram 1.1.II markl

that can be used in the circuit in

Diagrotn 1.2Which ammeter is more sensitive?

Ammeter X Ammeter Y

(i)

IL mark)

SPM 2006 PHYSICS P2


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(ii) State one reasonfor your answer in l(bXi).

(b)

IL mark]Diagram 2 shows a mercury thermometer which has not been calibrated.

MercuryDiagram 2

(a) (il state the physical change in the mercury when the temperature increases.

IL markl(ii) Why is mercury used in the thermometer?

tL mark|The length of the mercury column in the thermomet"" i, 2.6 cmat 0 qC and 22.6cm at1000c.(i) What is the difference in the lengths of the mercury columns at 0 oCand at 100 qC?

(ii) When the thermometer is placed in hot oil,16.9cm.Calculatethe temperature of the hot oil.

ll mark]the length of the mercury column is

[2 marhs]


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Diagram 3 shows two loudspeakers connected to an audio frequency generator.students are standing at positions where loud. sounds can be heard.

Loud speaker Audio frequencygenerator

Diagram BWhat type of wave is the sound waves?a)

IL mark](b) why are loud soundsheard by the students at that positions?

IL mark](c) The distancebetween he two loudspeakerss 1.5m. At 10.0m from the loudspeakers,hedistancebetweentwo adjacent rows of students is 4.0 m.Calculate the wave length of this sound wave.

12marhsl


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(d) The frequency of the sound wave is increased.(i) What -will happen to the distance between two adjacent rows where loud sounds areheard?

U markl(ii) Give a reason for your ansvrer in S(dXi).

[l rnark].Diagram 4.1 showsa submarine equipped yith an optical instrument pDiagram 4.2 shows the structure of the optical instrument p

Optical instrument P

Glass prism

Observer

Diagram 4.1Light rayfrom the object

(a) Name the optical instrument pDiagrarn 4.2

[l markT


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(b) In Diagram 4'2, tw.oglassprisms-must be placed.so hat the objectcan be seenby theobserver.The position of one of the glassprir*, is as shown.(i) In box A in Diagram4.i, a."* and shade he secondprism.LLm',arkl(ii) Explain why the prisms in optical instrument p are placedas in 4(bxi).

IL rnark](c) (i) In Diagram 4'2, completehe path of the light ray from the object o the observer,s ye.IL mark](ii) State one characteristicof the image observed.

IL m.ark](d) The refractive index of the glass prism is 1.b2.Calculate the critical angle of tfru glass prism.

12markslDiagram 5'1 show the situation of a sheet of paper before and when air is blown.Diagram5'2 shows he situation of the canopy irore the lorry movesand when the lorry movesat high speed.

Before air is blownDiagrarn 5.1

When air is blown


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\rLzBefore lorry moves When lorry moves at hight speed

Diagram 5.2(a) What is meant by speed?

G)lL marbl

Basedon Diagram b.1 and Diagram b.2:(i) State trro sirnilarities for the situation in Diagram 5.1 and Diagram b,2.1.

2.

A marksl(ii) compare the air pressureaboveand below the paper when air is hrown.

IL mark](iii) Relate the speedof the air to the pressureof the air.

U m.arkJName the principle involved in E(bXiii).

IL mankJ


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(d) Diagram 5.3 shows an instrument usedTubeA

to measure the speed of air.TubeA

Diagram 5.8lp Dla8ram 5.3, the levelsof colouredwater in the(i) Compare he speedsof air at p and at e, -- U-tube are the samebeforeair flows.

lL mark-(ii) Mark the water levels in the u-tube in Diagram 5.8 while air flows.lL marklDiagram 6'1 and Diagram 6.2 showa student throwing an iron ball in a shot put event usingifferent throwing techniques.The angle of projectiott uttd the force used by the student in both techniquesare the same.

ii

Before air flows While air flows

Diagrarn 6.1


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I'lBIrA

(a)Diagram 6.2

ObserveDiagram 6.L and Diagram 6.2.(i) compare the distance of the hand movement to throw the iron ball.

II mark](ii) Basedon the anjswern 6(aXi), compare he work doneby the studentbetween he twothrowing techniques

IL mark](iii) If the force which acts on the iron ball is 20 N and the distance of hand movement is0.5 m, calculatethe work done by the student.

IL markl

t2 marhs.l(b) (i) Basedon the answer in 6(a)(i), state the relationship between the enerry gained bythe iron ball and the distance of projection.

(ii) State the principle involved.

U markl


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(c) (i) using Diagram 6.1, what happens to the falling time if an iron ball of a bigger massis used?

LLmarkl(ii) Give one reason for your answer in 6(cXi).

IL mark]A student wants to build asimple lift motor control systemwhich operatesusing two buttons,A and B, for a two-storey building.A : Up buttonB : Down buttonThe lift motor only activateswhen someonepressesany one of the buttons.Diagram 7.1 showsthe circuit that can be used to activate the motor.

12V

Diagrarn 7.1Keys:Buttons A and B : When pressed, logic "1"logic "0"ot pressed,X Output : Motor is activated, logic,,l,'

(a) Table 7 is a truth table which shows he operationsof the logie gates n a lift motor controlsystem.A B X0011

0101

Table 7


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(i) Using the keys given, completeTable Z.(ii) Name the logic gate in the circuit in Diagram 2.1.

L2marksJ

IL mark)(iii) In the spacebelow,draw the logie gate symbol in Z(aXii).

lL markl(b) Why is a relay switch needed n the circuit?

lL rnarklThe door of the li{t is fitted with a light transmitter and a detector which is a lightdependent resistor.If.-the light dependentresistor detects light, the relay switch is activated and the lift doorwill close.Diagram 7'2 shows an electronic circuit for the control system of the lift door.

l ,tR!_

(c)

Diagram 7.2


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(i) State the relationship between the resistance and the intensity of light received by thelight dependent resistor.

[1 mark](ii) Complete the circuit in Diagram 7.2 by drawing the resistor and the light dependentresistor using the qrmbols given below.

$ight dependent resistorIilI

Resistor(iii) Explain how the circuit functions.

l3 marhslDiagram 8.1 and Diagram 8.2 show two identical mirrors which are hung on the wall usingstrings, of the same length.

The two mirrors are in equilibrium state. Each mirror has a massof 2 kg.Each string canwithstand a maximum force of 15 N.

fL markl_.

Diagrarn 8.1 Diagram 8.2


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(a) What is meant by equilibrium state?

IL mark](b) What is the weight of any one of the mirrors?

[l markl(c) In the space below, draw a diagram of a triangle of forces that acts on the mirrors inDiagram 8.L and Diagram 8.2.

L2marksl(d) 11 and Tr^are the tensions of the strings that act on the mirrors in Diagram 8.1 and

Diagram 8.2 respectively.(i) In the spacebelow,draw the scaledrawings.of the triangles of forcesto determine thevalues of T, atrd Tr.[Use the scale1 cm: 2 N]

Diagram of a triangleof forces for Diagram 8.1 Diagrar4 of a triangleof forces for Diagram 8.2

T1N

cmN

T2

L4marksl


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(ii) Based on your answer in 8(dXi), which is the most suitable method to hang the mirror?Give one reason for your answer"

12 marksl(e) If the string in Diagram g.1 is cut, the mirror will fall down in 0.6 s.calculate the final velocity of the mirror before it touches the surface of the floor.

IZ marks)Section B[20 marks]

Answer any onrequesti.onfrom this section.The time suggestedo answer this section s S0 minites.Diagram 9'1 and Diagram g.2 show the light rays from two identical objectspassing hroughthe convex enses,J and K. Both the lenJes prldo"" il";i;.*" iI* the focar point foreach ens. f .r_| - \ -| \ \' \ \| \ -Imagei -----

: -Object Principal

Diagram 9.1r f i :

\ \Object

Lens J

lxrs

axrs

Lens K

Image

Diagrarn $.2

Principal


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(a) (i) What is meant by virtual image? U markl(ii) with reference o Diagram 9.1 and DiagraT g.2, compare he thicknessof the lenses,the focal length and the size of image p"oducedby the lensesJ and K.Relatethe sizeof the imagewith the focal length io make a deductionregarding therelationship betweenthe power of the lens and the focal rength. IE marks)ft) Explain why a pieceof paper burns when placedunder a convex ens aimed towards hotsun rays. [4 marks)(c) You are given two convex enses,P and Q, with focal lengths 40 cm and b cm respectively.Both the lensesare used to build a simiie astronomicaltelescopeat normal adjustment.(i) using the two lenses,explain how you are going to build the simple astronomicaltelescope. 16marksl. (ii) suggest modifications that need to be done on the telescope o produceclearer andbigger images. [4 marks]Diagram 10'1 and Diagram 10.2showwire coils connected o the ammeters,switchesand d.c.ower supply.

Wire coils

Pattern ofiron filings

Ammeter

Diagram 10.2

Cardboard

To d.c. powersupplyDiagram l0.l.

To d.c. power supply

When the switch is on-and ron filings of the sameamount is spreadon eb.ch f the cardboardsurface, he pattern of the iron filings is formed as shown i"-irr" ai"gr*r.


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(a)ft)

What is meant by magnetic field? II mark]using Diagram 10'1and Diagram10.2,compare he numberof turn of the coils, he patternof the iron filings and angle of deflection of the ammeter indicator.

[3 marks](c) state the relationship betweenthe strength of the magnetic field and(i) the pattern of iron filings,(ii) the number of turn of the coils.

[2 marksl(d) Diaeram 10'3 showstwo thin copperstrips, PQ and RS, connected o a circuit.

Diagram 1O.BExplain what happens o pe and RS, when the switch is on.Diagram 10.4 showsan electric motor which is supplied with a. 12 y a.e.

Carbon,brush

Slip ring

External circuitDiagram 10.4

[4 marksf


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(i)(ii)

Explain how the motor is able to rotate.

Section Cl2OmarkslAnswer any olne question from this section.The time suggest o answer this section s s0 minutes.

What is meant by specific latent heat of vapourization?

[4 marks]

[6 marhs]

IL mark]

Time/min

Using a Il V a.c.power supply,explain the modifrcation hat needs o be doneon themotor and the external circuit to enable he motor to be a d.c.electricmotor and rotatefaster.

(a) (i)(ii) Explain why someone who is sweating feels cool when he is under a rotating fan.

14marhs)(b) A solid substanee'of mass0.05kg, is heatedusing an immersion heater of 240V 0.1 kr41Diagram 11.1 showsthe heating eurve of the ,on-a.Temperature/lC

Diagram 1l.lCalculate(i) the specific latent heat of fusion of the substance,(ii) the specific heat capacity of the substance n liquid state.

[5 marksf


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(c) You are asked to investigate the features of cooling material and the desiga of a car engineradiator as in Diagram 11.2. --oExplain the suitability of each feature_s n Diagram Ll.2 and, hen determine the mostsuitable car engine radiator to be used.Give a reason for your choice.

blade

The features of cooling liquido Boiling point 100 qCo Specific heat capacity 4 2A0 J kgr og-r

blade

The features of cooling liquid. Boiling point 100 oCo Specificheat capacity 4 200J kgr og-r

Fin ----5 hThe features of cooling liquido Boiling point 100 qCr Specific heat capaclty 4 2ffi J kgr og-r

Fin ------_s T?re features of cooling liquido Boiling point 78 qCo Specificheat capacif 2 480J kgr og-r

Fin _____=$

The features of eooling liquido Boiling point Z8 oCo Specificheat capacif 2 450J kgr og-r

[70 marks]

Diagram 11.2


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12 Radioactive material has some uses in the medical field such as in the investigation of internalorgans and in the sterilization of equipments.(a) A doctor conducts an investigation on a patient's kidney by injecting iodine-131 radioisotope,that a half-life of 8 days, into the blood circulation. iA normal kidney can expel the radioisotope in 20 minutes.The preselce of radioisotope in the left and right kidneys is shown in the graphs as inDiagram 12.1.Activity

l0 15Right kidney

Diagram 12.1(i) what is meant by half-life? IL markl

(ii) Based on the graphs in Diagram 12.1, which kidney is not functioning properly?Give one reason. 12 marksl(iii) The initial iodine-l3l activity is 1 600 counts per second.Calculate the time taken for the iodine'L31 activily to decrease o 100 counts per second.[2 marks)(b) Medical equipment is sterilized by radiation from a radioactive source.You are assigned to study the characteristics of some radioisotopes that are suitable foruse in the sterilization of medical equipments.Table 12 shows the characteristics oi r.t e radioisotopes.

Time/minuteime/minuteLeft kidney

Characteristics of isotope

Strontium-90Cobalt-60Xenon-133Iodine-131Polonium-Z10

SolidSolidGasLiquidSolid

BetaGammaBetaGammaAlpha

28 years5 yearsb days8 days140 days

Table 12


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(i) Explain the suitability of the characteristics of the radioisotope to be ,rs"a i' tt bsterilization of medical equipment. ' [6 marks](ii) Determine the most suitable radioisotope to be used and give one reason for your

L2 marksl(b) Gamma rays can produce an effect on photographic frlm.

Explain whether grmmarays is suitable to be used in taking photographs of an organ inhumans' -o r-----E IB marksf(c) Beryllium-11 isotope emits two rays. The isotope is placed in front of a magnetic field andthe radioactive radiation path is shown in Diagram L2.2.

Radioactivesource

Diagram 12.2(i)(ii)

Name both rays that are emitted by the isotope.Explain why the rays follow the path shown in Diagram 12.2.

12marksl[2 mnrksl


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Paper 2Section AI (a) (i) Voltmeter(ii) To vary the resistance in the circuit

&) (i) Ammeter Y(ii) The scale of ammeter Y can measurecurrents accurate to 0.05A whereas thescaleof ammeterX canmeasurecurrentsaccurate to 0.1 A.(i) Mercury expandswhen the temperatureincreases.(iil Mercury can be seen easilY.(i) 22.6 cm - 2.6 cm: 20.0 crn(iil By interpolation,

22.6 - 2.6 100- r2L6-L6 = 196-65.7 100 rn:1oo574f r = 1oo-r28.5 = 100-rx = 100-28.5x : 71.5oC

(a) Sound wave is a longitudinal wave.(b) The;loud sound heard by the students areproduced by constructive interference.(c) ^ axc where a = 1.5 rn:

(al

(b)


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'l'he prisms in optical instrument P areplaced as in 4(b)( i ) because thisarrangement allows light rays from theobject to be reflected by 90 einto the lowerprism and out to the eyesofthe observer'Total internal reflection occurs in bothprisms.Path of light raY

The image is upright/same in sizeIC =- n

(i) The distance of projection increases '13the enerry gained increase.(ii) The principle of conser-vationof enerst(il Same(ii) Iron ball is thrown from the sameheigtrtTime taken is independent of the nrir"*s =u.t

Uorf,=

(b)

(c)

1-+ Tgt"u(c) (i )

(ii)(d) sin

(a) (i)

7 \a) (i )

(b)(c) (i)

(ii)

(ii) OR gate(iii) A F.| --l/

(a)

. , /1\c = srn_,tn/"( 1\c = sin_'[ Ln )

c = 4l.l4eSpeed is the rate of change of distance.Mathematically it is given bY

, distanceDpeeo = me-[;E6n(il 1. Movement of air'2. Paper and canoPYbeing lifted.(ii) The air pressure abovethe paper is lowerthan the air pressure below the paperwhen the air is blown.(iii) High speed of air creates low pressure'Bernoulli's principle(i) The speed of air at P is higher than thespeedof air at Q.(ii) p a

ColouredwaterThe distance moved by the student'shand in Diagram 6.2 is more than thedistance moved by the student's hand inDiagram 6.1.The work.done in Diagram 6.2 is moreas compared to work done in Diagram6.1.Work done = force x distance=20X0.5= 10J

Motor uses high voltage. Relay switch i*used for safety reason.Asthe intensity of light receivedby the liglridependent resistor increases, he resistaneof the light dependent resistor reduces'

(b)

(c)(d)

(ii) I (a)

(b)

(iii) When the LDR detects light from thelight transmitter, its resistance falls taa small value. The potential differenceis dropped acrossthe LDR, thus raisingthe potential difference across theresistor and base current is increased'The transistor is switched on. Collectorcurrent flows and the relaY is thenactivated.

Equilibrium state is the state of an object inwhich the resultant force acting on the objectis zero.Weight of mirror = 2 x 10 = 20 N

A B x0 0 00 1 1I 0 I1 I I

(iii)


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5.8 cm (11.6N)

20 N (1 0 cm)5.8 cm (11.6N)

By scale drawing:T, = 5'8 cmT, = 11'60N

7 cm {14 N)

20 N (1 0 cm)7 c m (14

By measurementTz = 7'10cmTz = 14'20Niiil 'fhe most suitable method to hang themiror is the one n Diagram 8.1. This isdue to the fact that the tension in the*tring T, is lower in value than Tr.(r:i $y *cing the equation.V * u *gff take u = 0 m s-r as themirror falls from rest.We have,f ,* $+10(0.6)Y * Sms- '

B{a} tii A virtual image is an image that cannotba *aptured on a screen.iii] l.*ne J is thicker than lens K" The focallength of lens J is shorter than that of

Lhe ens K. The image produced by lensJ is taller than that produced by lens K.A thicker lens will have a shorter focallength whereas a thinner lens will havea longer focal length. According to theequation fo r power of a lens, P - Lf 'where f is measured in m, a lens havinga shorter focal length will have a higherpower.A lenswith longer focal length willhave a lower power.

ft) When the rays of the hot sun from infinity,passthrough a convex lens, they are refractedand converge at a point called the principalfocus of the lens" At the principal focus theimage of the sun is concentrated on a verysmall area and the intensity of sunlight isgreat. The intensity of sunlight warms up thearea on the paper and as the temperature ofthe spot becomes high enough, the paperstarts'to burn.(c) (i) I have two lenses.Lens P and lens Q withfocal lengths of 40 crn and 5 cmrespectively. To make a simpleastronomical telescope, I will have tofocus the starlight at a certain point. Forthis, I will have to used lens P whichhas a focal length of 40 cm. I will use thelens Q as the eyepiece lens with a focallength of 5 cm.I will arrange the telescope as shown

below.Objective lens Eyepiece lens

Starlight

Diagram of atriangle forcesfor Diagram 8.1(d) (i)

Diagram of atriangle forcesfor Diagram 8.2

f -f -

focal length ofobjective lensfocal length ofeyepiece ens

4 = focal length ofobjective lensF. = focal length ofeyepiece lens

Parallel rays of starlight from distantstars converge at the focal point of theobjective lens to form an initial imagewhich is real, inverted and smaller thanthe actual object. This image thenbecomes he object for the eyepiece enswhich is formed at infinity. Under normaladjustment, the final image seen.by theobserver is magnified, inverted andvirtual. The length of my telescope willbe approximately 40 cm * 5 cm = 45 csr.


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lens.- Increase the focalobjective ens.- Reduce the focaleyepiece.

length of thelength of the

such as

lncrease the diameter of the objective The force on ab of the ammature isdownwardswhile the forceon sidecd irrDiagram (a) is upward. These wo forcesprod*"" a couPle which rotate tht 'armature. This rotation will continut'unl i l the armature s in the hor izonlrr lposit i r - rnDiagram again as shown rrrDiagram (c). The alternating currenlcharges direction and current flows indirection as shown in Diagram (c)' The:process continues to rotate the motoruntil the current is cut off.- Replace the sl iP r ings with acommutator' The commutator is trrenable a smooth change of directiotlof the current flow in the armature srtthat the armature will continuouslyrotate in one direction onlY'The strength of the magnetic fieldmust be increased.

The number of turns of wire in thearmature must be increased'- The area of the armature must beincreased.- The armature must be wound over asoft iron core.

Specific latent heat of vapourization isthe amount of heat required to change1 kg of a liquid into vapour at a constanttemperature.When a fan is rotat ing, there i*circulation of air. Latent heat ofvapourization is absorbed rom our bodywhen the sweat evaporatesaided by thecirculation of air. The body feels cool bythe removal of heat.The specific atent heat of fusion is givenby the relation.

- Reduce the obstruct ionssupportingstruts.0 (a ) A magnetic field is a region in which amagnetic material will experiencea force dueto the presence of a current carryingconductor-(b) The number of turns of coils in Diagram 10'2is greater than the number of turns of coilsinbiagram 10.1. The pattern of iron filingsformeJ on the cardboard in Diagram 10'2 isdenser than the pattern of iron frlings formedin Diagram 10.1.The current in Diagram 10'2is higher than Diagram 10'1'(c) (i) iVtt"tt the strength of the magnetic fieldincreases, the pattern of iron filingsformed is denser.(ii) When the number of turns of the coilsincreases, the strength of the magneticfield also increases''''(d) Wh"r, the switch is switched on, current willpass through strips RS and PQ as shownbelow I Il l

YI" --l l ll lA force will be exerted on each strip asa resultof the magnetic field created' Currentcarrying copper strips with currents inopposite directions produce a strongermagnetic field in the region between thestrips. This is because he magnetic lines arein t-hesame direction. The two copper stripsrepel each other.(e) (if When the power supply is switched on'electric current flows in the directionshown in the figure below' The carbonbrushes are in contact with the slip rings'g{s&)s

L-.= L-:=Jaflw-FiL:]

(ii)

Section B11 (a) (i)

ft) (i)

(ii)

Pt :mlwhere Pmtt, -Pt-m

: 0.1 x l-03W= 0.05kg= (3.6 1.0)x 60= 156s

" 0.1 x 103x 156L - 0.05= 312 000 J kg:'(ii) Th e specific heat capacity of the

substance in a liquid state is given bythe relation.Pt = mcOPtc =-m(d)


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(c)

where 1) - {}. l {} ' \ ,1 ;r t) { )5 kgf l . . r2lS is; i l l | " ( 'I . t l i i ; i { ; r { ; { l....' ..

I ' t, , , , r ,{ l . l ' r l t } - i2/ ' =' ( ] { }5 " l4o1()!t{.ir?J [is t 91 t

- The fhn musf lit' l lrgc sti t,lral t can cooldown ir larp4er re*r.- Fin blades milt{t b{' a$ }n:in"yas possibleand scattered o f'aexrhe firn so that it canbe icooleddown errsily.* lloil ing point of't,he rxrling iquid must behigh sn th&t it won't boil easily.- Specifie &padt"y f the liquid must be argeso thal it can absorb argeamount of heat.- The rnostsuitable radiator is P because thas arge an, many fin blades,highboilingpoints and high specific heat capacity.(i ) The halflife of a radioisotope s definedas he time taken for the activity of atomsof that radioisotope to fall to half itsinitial value.(ii) 'Ihe right kidney is not functioningproperly.This is due to the fact that thereis st i l l act iv i ty of the iodine-131radioisotopedetected n the right kidneyafter 20 minutes. If the kidney is normalas in the case of the left kidney, it willexpel the iodine-13l radioisotope n 20minutes.

(ii) The most suitable radioisotope s cobalt60 because t is in solid form, emitsgamma ray and has a half life of 5 years.(c) Gamma rays can produce a negative effecton the organs f a high dose s used as it hashigh penetrating power.As such it is notrecommended o use gamma rays to takephotographs of an organ. X-rays with lesspenetrating power are used instead.(d) (i ) The rays emitted try the Beryllium-l1isotopeare beta particles and gamma ray.(ii) The beta particles is negatively chargeand will be attracted to positiveelectrode.Gamma rays has no charge and will notbe deflected bv electric fielC.

Paper 3(a) (i) Temperature(ii) The length of the column of air.

(iii) The length of the column of concentratedsulphuric acid.(b) (i) The eye must be at a position level withthe top of the trapped air column.Temperatures0(rc) Length of aircolumn, I (cm)

0 7.t20 7.630 7.940 8.150 8.460 8.770 9.0

@) tt"

(iil

(i i i) The initial iodine-131activity is 1600countsper second.The time taken for theiodine-131activity to decrease o 100eounts per second s given by1600counts per second 1 half-life)8f)0 counts per second (2 half-lives)400 eounts per second 3 halflives)*00 counts per second (4 half-lives)100 c unts per second1#'e equire 4 half-lives, one half-life isi l e lays.As such 4 hal f- l ives wi l l be!{ .' { * 32 days.{ht {i } * 'Ihe radioisertope ust be n solid ormsr that handling is easy.. Ttt* typcr ol' ray emitted must be

Ssmrnel r$ys because i t is an*leetrcmagnetic waves of highf**quency Bnd penetrating power to

spm 4531 2006 physics p2 berjawapan

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