answer section b and c and paper 3

5/19/2018 Answer Section B and C and Paper 3

1/21

ANSWER SECTION B AND C

1. (a) (i) The bending of light as it propagates from one medium to another

(ii)

Thickness of slab in Diagram 11.1 is thinner The size if image in Diagram 11.1 is smaller

Position of image in Diagram 11.1 is nearer to bottom

The thinner the glass slab, the nearer the image is to the bottom

The apparent depth increases as real depth increases

(b) The transmitter is placed at the focal point of the dish.

The parabolic dish is focuse to the radio satellite

The radio waves is reflected back to Earth to a receiving dish

The parabolic dish focuses the radio waves onto the receiver which is

placed at the focal point

(c) Aspect Reason

Concave mirror magnified image

Large surface area Increases field of view

Large radius of curvature Bigger image

Longer focal length Bigger image

Less than focal point Bigger image and upright


2/21

2. (a) (i) Total internal reflection

(ii) Objective lens: to produce a real, inverted and magnified image

Eyepiece: to produce a virtual, upright and magnified image // a

magnifying glass

(iii) can carry large amount of data/information // transmit signals

with very little loss

of energy // very much thinner and lighter // can be bent around

corners

(b) - Object distance: Diagram 9.2 < 9.3

- Image distance: Diagram 9.2 > 9.3

- Image size: Diagram 9.2 > 9.3- The bigger the object distance, the smaller the image distance

- The bigger the image distance, the bigger the size of the image

(c) Aspect Reason

Shorter focal of objective lens High power

Longer focal length of

eyepiece lens

To magnified the image

Object between F and 2F To produce a real, inverted

and magnified image

Bigger than objective lens Image produce always less

than focal

More than fo+ fe Produce image at normal

adjusment

Dry condition Prevent fungus


3/21

3. (a) Unstable nucleus become more stable nucleus

(b) (i) Negative

(ii) In Diagram A, the EHT is of lower voltage. The deflection is

less.

In Diagram B, the EHT is of higher voltage. The deflection isgreater.

(c) (i) When the voltage is higher, the strength of the electric field is

greater.

(ii) When the strength of the electric field is greater, the deflection

of the radioactive emission is greater.

(d) (i) Nuclear fission

(ii) -

Mass defect during the reaction.- The mass defect is converted to energy.

- The energy produced, E, is given by E = mc2 where m =

mass defect, c = velocity of light in a vacuum.

Aspect Reason

Use tongs/distance controller. so that the distance between

the source and the body is far

Wear a mask the radiation does not

penetrate our eyes

Wear a film badge to detect the amount of

radiation exposed

Wear a radiation proof coat the radiation does not

penetrate the body

Use a lead box/container with

thick concrete

to prevent radiation leakage to

the surroundings

Put a radioactive symbol on

the storage box

to inform users of the

dangerous contents of the box

Keep the exposure time as

short as possible

the body is not exposed to the

radiation for a long time


4/21

4. (a) Doping is a process of adding a certain amount of specific impurities

to semiconductors to increase their conductivity

(b) - Diagram 2.1, the p end of diode is connected to negative terminal

of dry cell // Diagram 2.2 the p end of diode is connected topositive terminal of dry cell

- Bulb in Diagram 2.1 does not lights up

- No current flow in Diagram 2.1 // Current flow in Diagram 2.2

- The bulb will lights up when the p end of diode is connected to the

positive terminal of dry cell // vice versa

- Current only flow in the circuit when p end of diode is connected

to positive terminal of dry cell or in forward bias

(c) (i)

(ii)

- Capasitors store charge when current flow

- Capasitor discharge when current does not flow

(d) Aspect Reason

LDR is replace by termistor

/ diagram

resistance decrease when

temperature increase

Termistor is place at R1

and R1replace LDR /

diagram

So that V across R1 increase when

the room is hot

Relay switch replace LED

To switch on secondary circuit /to

switch on the fan

Fans are arranged parallel

All fans received 240 V power

supply / other fans still functioning

even though one fan did not function

Resistor connected to the

base of transistorlimit the current to the transistor


5/21

5. (a) Speed is the distance per unit time

(b) Speed limit is imposed because:

Momentum depends on mass and velocity. The momentum of avehicle is high when it travels in high velocity. A high

momentum will cause a high impulsive force during a collision

Load limit is imposed because:

Inertia depends on mass. The inertia of a vehicle is high when it

carries more load. It is difficult to stop a moving vehicle which is

carrying a big load

(c) Aspect Reason

ABS is more effective than air

brake

lorry can be stopped

immediately without skidding

Two tyres are better than one

tyre

provides better support

5 small tanks are better than 1

big tank

5 small tanks will have smaller

inertia compare with 1 big tank -

reduces the inertial impact on

each tank if the tanker stop

suddenly

Further distance is better to prevent collision between the

trailer and the tractor

S ABS, More tyres, 5 small tanks,

further distance

(d) (i)v =

49 10

3600

v = 13.611 m s1

v = u + at13.611 = 0 + a(12)

a = 1.134 m s2

(ii) F = ma

F = 2 410 1.134

F = 2 733.56 N


6/21

SECTION C

1. (a) The degree of hotness

(b) -

The thermometer is put under the tongue/inside the mouth- The heat is transferred from the body to the thermometer

- Alcohol liquid expand until it reaches a state of thermal equilibrium

- The temperature of the thermometer is the same as the body

(c) (i)C

LL

LLx

x

o1000100

0

=

Cxo100

525

512

=

Cxo

35=

(ii) (35 + 273)K = 308K

(iii)C

LC oo 100

20

530 30

=

1130 =L cm

(d) Aspect Reason

Freezing point is low/

Freezing point < -65C

- To prevent liquid freeze at -65C/

Not easy to freeze/ The thermometer

can be used to record temperature at -

65C

Boiling point is high/ Boiling

point > 20C

Not easy to boil/The thermometer can

be used to record temperature at 20C

Opaque/Clear red in colour Easy to observe the reading of

thermometerThin glass wall of bulb More sensitive to heat

R is chosen Because it has freezing point < -

65C, high boiling point > 20C,

Clear red in colour and thin glass

wall of bulb


7/21

2. (a) Power is the rate of work done.

(b) 1. Reading of ammeter increases.

2. Effective resistance decreases.

3.

Reading of the voltmeter decreases.4. The effective resistance between XY decreases.

(c) (i) R = V2 = 6

2

P 18

= 2

(ii) 1 = 1 + 1 + 1

R 2 2 2

R = 0.67

(iii) E = Pt

= 3 X 18 X 2 X60

= 6 480 J

(d) Aspect Reason

Density of wire is small Lighter

High melting point Will not melt at high temperature.

Rate of oxidation low Does not rust easily.

Resistivity is highMore heat energy is produced.

M is choosen.

Because small density, high melting point, rate of oxidation is low

and high resistivity.


8/21

3. (a) Produce of induc

(b) (i) A curr

changi

(ii)

c

m

T

c

A

v

th

(c) As

Soft iron

Resistance per

low

Ratio of Ns/Np

same as Vs/Vp

The core structu

laminated, henc

of many layers.

Transformer N i

(c) (i) NO A (ii) P= IV

24 = (I

I = 2 A

(iii) Output

80% =

= 30W

e current by cutting of the magnetic flux

nt is induced in the secondary coil when

g magnetic flux due to a changing prim

hen a.c voltage applied to the primary c

rrent flows through the coil, the soft iro

agnetized

is means the magnetic flux linkage in t

il is constantly changing

n alternating emf induced across it to ind

ltage in the secondary coil and a.c curre

rough the secondary coil.

ect Reason

Can be magnetised an

demagnetised easily.

etre must be so that less heat is lost

loss.

ust be the

re must be

must be made

So that resistance of t

increased and eddy cu

reduced.

s most suitable As it has a soft iron co

lowest resistance per

and the

up of a large number

SWER

12

power/ input power X 100%

24/input power X 100%

.

there is a

ry a.c current.

il, an a.c

core is

e secondary

uced a.c

t flows

/less power

e core is

rrents are

re, wire of

etre, has ratio

core is made

f layers.


9/21

5. (a) Tekanan atmosfera// ketiinggian// ketumpatan

(b) 1. Ubat drpd botol IV digantung supaya lebih tinggi dprd

pesakit

2. Tekanan bendalir dalam botol IV menjadi lebih tinggi dprd

vena pesakit3. Bendalir akan mengalir dari kawasan tekanan tinggi ke

tekanan rendah

4. Ubat akan dapat memasuki vena pesakit kerana tekanan

bendalir ubat yang tinggi

(c)

d. (i) P = F/AP = 50 N/2 cm

P = 25 N cm-2

P = F/A

F = P x A

F = 25 x 15

F = 375 N

(ii) V1= V2A1h1= A2h2

2 x 21 = 15 x h2

h2= 2.8 cm


10/21

6. (a) Prinsip Archimedes

(b) 1. Total density of ship < density of water2. Buoyant Force = Total weight of ship

(c) - Volume of water displace increases- Produce bigger buoyant force.

(d)

(d) (i) Volume of water displaced = Volume of wooden block

= 3/800

= 3.75 x 10-3

m3

(ii) Weight of load + Weight of wooden block = Weight of water

displacedWeight of load + Weight of wooden block = Vg

Weight of load + (3 x 10) = 1000 x 3.75 x 10-3

x 10

Weight of load = 37.5 30

Weight of load = 7.5 N

Mass = 0.75 kg


11/21

PAPER 3

SECTION A

(a) (i) State the manipulated variable correctly

Time

(ii) State the responding variable correctly

Temperature

(iii) State the constant variable correctly

Mass of the water// power of the heater

(b) State the value of 0within the acceptable range

0= 25oC

(c) (i) Record the readings of correctly

All five readings of correct

(ii) Tabulate the results for t, and correctly

t / s /oC /

oC

20 32 7

40 39 14

60 46 21

80 53 28

100 60 35

Give a tick () based on the following:

A Columns t, and

B Correct units for t, and

C All 5 values of correct

D All 5 values of correct

[Note : 3 or 4 values of correct : ]

E All values of and

written as whole numbers orconsistent to 0.5oC.


12/21

Marks awarded :

Number of Marks

6 5

5 4

3 - 4

32 2

1 1

(d) Draw a complete graph of against t

Give a tick () based on the following:

A at the y-axis, t at the x-axis

B Correct units at both axes

C Uniform scale at both axes

D 5 points plotted correctly

[Note : 4 points plotted correctly : ]

E Line of best fit is drawn

F Minimum size of graph 5 x 4 big squares

(Big square: 2 cm x 2 cm)

(From the origin to the last point)

Marks awarded :

Number of Marks

7

55-6 4

3-4 3

2 2

1 1

(e) State the correct relationship between and t

is directly proportional to t


13/21

2. (a) (i) Decreasing linearly 1

(ii) 7.0

Show on the graph

1

1

(iii) Emf 1

(b) (i) Draw a sufficient large triangle.= 7 3/3 0= 1.33 Ohm/

111

(c) Show on the graph

V = 4.3 V

1

1

(d) E = I (R + r)

7 = 2 (R + 1.33)

R = 2.17 Ohm

1

1

(e) Eye perpendicular to the scale of ruler to avoid parallax error. 1

TOTAL 12 MARKS


14/21

SECTION B

Answer Marks

(a) (Induced) current is depends on the rate of cutting of

magnetic flux / (speed / height of magnet)

1

(b) (Induced) current increases as the rate of cutting ofmagnetic flux / (speed / height of magnet) increases

1

(c) i. To study the relationship between (induced) current and the

rate of cutting of magnetic flux / (speed / height of magnet)

1

1

1

1

1

1

1

1

ii. MV: Rate of cutting of magnetic flux (height of magnet, h)

RV: (Induced) current,I (deflection of galvanometer)

CV: Number of turns of coil, strength of magnet

iii. Bar magnet, coil of insulated copper wire (solenoid), metre

rule, galvanometer(/ammeter)

iv

v. 1.The magnet is held at height, h= 10 cm, above the

solenoid. The magnet is dropped into the solenoid.

2.The induced current (deflection of galvanometer) is

recorded.

3.

The experiment is repeated with h= 20 cm, 30 cm, 40cm

and 50 cm.


15/21

vi.

Height of magnet, h(cm) (Induced) Current,I(A)

//Deflection of galvanometer

10

2030

40

50

1

1

1

vii

TOTAL 12

MARKS

Induced current,I (A) // Deflection of

galvanometer

Height of magnet, h

cm


16/21

3.

(a) Volume of trapped air depends on its temperature 1

(b) The higher the temperature the bigger the volumeof trapped

air

1

(c)(i) To investigate the relationship between volume and

temperature of trapped air

1

(ii) Manipulative : Temperature of trapped air 1

1Responsive : Volume of trapped air (length of air

trapped)

Pressure of trapped air // mass of air 1

(iii) Tripod, beaker, thermometer, Bourdon gauge, Bunsen burner,

rubber tube

1

(iv) Arrangement of the apparatus

1


17/21

(v) State the procedure including the way to control the

manipulated variables correctly

Water is heated and stirred until the temperature is 20oC. 1

State the procedure including the way to measure the

responding variables correctly

The pressure of trapped air is measure by using the Bourdon

gauge.

Record the reading of pressure in a table.

1

State the repetition of the procedure to obtain a set of data

The above procedure is repeated for a temperatures = 40

oC,60

oC, 80

oC and 100

oC

1

(vi) Temperature/oC Volume of air trapped/ cm

20

40

60

80

100

1

(vii) Draw the axes of y and x with label

1

TOTAL 12 MARKS

Volume ( cm )

Temperature (oC)


18/21


19/21


20/21

6 (a) The position of theKedudukan imej be

(b) The more the depth

will beSemakin bertamba

(c) (i) Aim of experiTo investigateMengkaji hub

(ii) Manipulated vPemboleh uba

Responding vPemboleh uba

Constant variaPemboleh uba

(iii) List of apparat

Tall beaker, wBikar tinggi, a

(iv) Arrangement

(v) Procedure:

1. A beaker iSebuah bik

2. The pointe

image depends on the depth of waterrgantung kepada kedalaman air

of the water is, the more the apparent de

kedalaman air, semakin bertambah dal

ent:the relationship between real depth andngan antara dalam nyata dan dalam ket

ariable: The depth of the water

h dimanipulasikan: Kedalaman air

riable: The position of the imageh bergerak balas: Kedudukan imej

ble: The type of liquid and the type of be h dimalarkan: Jenis cecair dan jenis bik

us and materials:

ater, pins, retort stand and metre ruleir, pin, kaki retort, dan pembaris meter

f the apparatus:

filled with water to a depth of 10 cm.ar diisikan dengan air pada kedalaman

r is moved to obtain the apparent positio

pth of the image

m ketara imej

pparent depthara

akerr

0 cm.

of the pin in the


21/21

beaker.Penunjuk digerakkan untuk mendapatkan dalam ketara pin dalam

bikar.

3. The apparent position of the pin in the beaker from the surface ofwater, d, is measured.

Dalam ketara pin dalam bikar dari permukaan air, d, diukur.

4. The experiment is repeated 4 times with the depth of water,D: 12

cm, 14 cm, 16 cm and 18 cm.Eksperimen diulangi 4 kali dengan kedalaman air, D: 12 cm, 14 cm,

16 cm, dan 18 cm.

(vi) Tabulate the data:

Depth of water,D/cm

Kedalaman air, D/cm

Apparent depth,d/cm

Dalam ketara, d/cm

10

12

14

16

18

(vii) Analyse the data:Plot a graph of apparent depth, dagainst the depth of the water,DPlot satu graf dalam ketara, d melawan kedalaman air, D

answer section b and c and paper 3

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