physics answer n9 08

8/14/2019 Physics Answer N9 08

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JPNS SPM TRIAL 2008

Answer P1 (Physics Paper 1)

1 A 11 C 21 B 31 B 41 B

2 D 12 C 22 C 32 A/B 42 C

3 D 13 D 23 B 33 A 43 A

4 D 14 C 24 C 34 A 44 A

5 C 15 C 25 Bonus 35 B 45 A

6 B 16 D 26 A 36 A 46 C

7 A 17 C 27 D 37 A 47 C

8 C 18 B 28 C 38 C 48 B

9 D 19 B 29 A 39 A 49 A

10 B 20 D 30 D 40 B 50 B


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TRIAL JPNS PHYSICS ANSWER PAPER 2

SECTION A

Question

Number

Answer Full

Mark1.(a) (i) base quantity is a quantity that cannot be defined in any other physical

quantity

1

(ii) ms-2

1

(b) Base quantity - time / displacement

Derived quantity - velocity / accelerationScalar quantity time

Vector quantity - displacement / acceleration

1

1

Total 4

Question

Number

Answer Full

Mark

2.(a) Convex mirror 1

(b) Convex mirror has a wider view than a plane mirror. 1

(c)(i)

Note :

Draw two incident rays and each of them reflected at thecorrect path.

1 mark

Shows image formed behind the mirror and the position infront of F.

1 mark

2

(ii) Virtual ,upright and diminished. (any of two combination) 1

Total 5


3/15

Question

Number

Answer Full

Mark

3(a) Step-down transformer 1

(b) A.u. power supply, Vp can produce a changing magnetic field thatinduces an alternating e.m.f in the secondary coil, Vs.

1

(c) Using a formula , Np = VpNs Vs

Np = 240V

Ns 12V

Np : Ns = 20 : 1

1

1

(d)(i) Bulb will not light up 1

(ii) Because transformer cannot function using direct current/cannot produce change in magnetic flux

1

Total 6

Question

Number

Answer Full

Mark

4(a) W = mg= (50)(10)

= 500 N 1

(b)(i) Increase 1

(ii) Decrease 1

(iii) Stationary / at 500N 1

(c) No resultant force/acceleration zero 1

(d) R = (46)(10)

= 460 Nmg-R = ma

500 460 = 50a

a = 0.8 ms-2

1

1

Total 7


4/15

Question

Number

Answer Full

Mark

5(a) Quantity of heat required to increase the temperature of 1 kg of material

through a temperature of 1oC

2

(b) (i) Energy output = power x time

= 3 x 103

x 3.5 x 60= 6.3 x 10

5J with unit

11

(ii) Energy required to raise the temperature of water,

Q = mc= 1.7 x 4.2 x103 x (100 -20)

= 5.71 x 105

J with unit

1

1

(iii) Energy required to boil away water,Q = ml

= 0.23 x 2.3 x 105

= 5.29 x 105

J with unit

1

1

Total 8

Question

Number

Answer Full

Mark

6 (a)(i) An electromagnetic waves is the vibration of electric and magnetic field 1

(ii) Can travel through vacuum

Speed of light

Transverse waves(any one answer)

1

(b) P : X-ray

Application : Radiotherapy for the treatment of cancerS : Microwaves

Application : Waves received by telephone and television signals from

satellite

1

11

1

(c) = v/f= 3x 10

8

3.2 x 103

= 9.375x104m

1

1

Total 8


5/15

Question

Number

Answer Full

Mark

7(a)(i) Function for safety purpose/To ensure the maximum weight limit 1

(ii) F = mg= 7500 x 10= 7.5 x 104 N

11

(iii) The mark should be higher than the sea water level 1

(iv) 1. density of sea water is denser than the density of river water.

2. the volume of water displaced increased when density of liquid decrease

2

(b)(i) Upthrust = Weight 1

(ii) Accelerates upwards or moves upwards 1

(iii) 1. the weight of the air balloon is decreased2. buoyant force /upthrust higher than weight

3. the balloon experiences the unbalanced force.(any two answers)

2

Total 10

Question

Number

Answer Full

Mark

8(a) (i) npn transistor 1

(ii) as a switch/automatic switchamplifier

11

(b) to limit the current to the transistor 1

(c)( i) VP increaseBecause resistance at P is higher

11

(ii) the transistor will switch on the relay switch

Ib will flow through the transistor and Ic will increase

1

1

(d) 10,000 x 6 = 2

10,000+ S

Resistance, S = 20 000 OR

RS = VS1000 + RS 6

RS = 20 000

1

1

(e) The bulb will not light upbecause it needs higher voltage/current to light up.

11

Total 12

SECTION B


6/15

Question

Number

Answer Full

Mark

9 (a) (i) Temperature is a measurement of the average kinetic energy of the atoms or

molecules in the substance.

OrTemperature is a measurement of degree of hotness of an object.

1

(ii) 1. The kettle is hotter than the ice block / The ice block is colder than the kettle.

2. The hand feels hot when it touches the hot kettle / The hand feels cold whenit touches the ice block.

3. Diagram 9.1 shows heat flows from the kettle towards the hand whileDiagram 9.2 shows the heat flows from the hand towards the ice.

4. The heat will flow from a hotter object towards a colder object.

1

1

1

1

(b) 1. Sea has higher specific heat capacity than land.

2. The temperature of the sea increases slower than of the land.

3. The air above the land is warmer than the air above the sea /Density of air above the land is lower than the density of air above the sea.

4. The warm air above the land rises up.

5. Air from the sea moves towards the land.

1

1

1

1

1

Modification Explanation

1.Use the fluorescent lamp not

a filament bulb

Fluorescent lamp use less power and

economic (consume less power) compare

to filament bulb

2. Bigger cover with white

colour

Less reflection on eyes and absorb less

heat energy and good heat reflector

3. Use the adjustable stand

Or portable

The height of the lamp can be adjusted

Can be used anywhere

4. Connect with the earth wire Avoid short circuit and damage on thebulb

5. Use an energy saver lamp Produce same brightness with less powerconsumption

2

2

2

2

2

Total 20

Question Answer Full


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Number Mark

10(a)(i)

1. Bulbs are connected in parallel 1m

2. Switch and battery are connected in series 1m

3. Correct symbols for all components 1m

3

(ii) When the bulb is connected to a power supply of 1.5V, it will produce 3J of

energy in 1 second.

1

(iii) The brightness of bulb A is the same as bulb B 1

(iv) I = P/V

= 6/1.5= 4A

11

(v) Energy = Pt= 6 x 3600

= 21 600 J

OrEnergy = VIt

= 1.5 x 4 x 3600

= 21 600 J

1

1

(b)

Modification Explanation

Resistance of wire is low to prevent power loss due to heat

Melting point is high to prevent the wire from melting

Density wire is low to reduce the mass of wire / too heavy

Rate of rusting is low to prevent it from rusting easily

Rate of expansion of wire to prevent lengthening of wire

22

2

22

Total 20


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Question

Number

Answer Full

Mark

11(a) Pressure is defined as the force acting normally per unit area/

Pressure = Force

Area

(b) 1. When the small piston is pulled up, the hydraulic oil is drawn from thereservoir into the small piston

2. When the small piston is pushed down , the hydraulic oil is exerted with

force and experienced a pressure

3. The pressure is transmitted uniformly from the small piston to the bigpiston.

4. The forced produced raised the big piston / The system can convert a small

input force into a bigger output force.

(c)Characteristics Reason

Has higher boiling point So that liquid not easily boiling/

Has higher specific heat capacity So that it cant be easily become hot

Has lower density So the hydraulic jack is not heavy

Has lower rate of vaporisation Volume of liquid will not easily vaporise

Liquid L is chosen Reasons: L has higher boiling point, higherspecific heat capacity, lower density and

lower rate of vaporisation

2

2

2

2

2

(d) (i) Weight = mass x acceleration of gravityW = mg

W = 60 x 10

W = 600 N

1

1

(ii) Pressure = Force

Area

A = F = 600 NP 500 Pa

= 1.2 m2

Minimum area of each snow shoe = 1.2 = 0.6 m2

2

1

1

1

Total 20


9/15

Question

Number

Answer Full

Mark

12(a) Reflection of waves 1

(b) (i)

(any two comparisons)

Radio waves Sound waves

Transverse waves Longitudinal waves

Can travel without medium Needs medium to travel

Have long wavelength Have short wavelength

2

(ii) The distance between the water molecules is closer compared to air molecules.Thus, the sound energy can be transferred faster.

11

(c) Characteristics Reason

Type of waves - longitudinal Because sonar is a sound waves

which is a longitudinal wave

High frequency Has high energy / can penetrate

deeper into the sea

High speed Can travel faster

High penetrating power Can penetrate through medium easily

The most suitable waves is S Because the waves is longitudinal ,

high frequency , high penetrating

power and has high speed.

2

2

2

2

2

(d)(i) d = vt2

= 1500 x1

2x 15= 50 m

1

1

(ii) To detect the depth of seabedTo detect the position of crude oil or sunken ship

To detect the condition of baby in the womb.Any two answers

2

Total 20


10/15

PHYSICS : ANSWER PAPER 3

Question

Number

Answer Full

Mark

1(a) i. Real depth,H 1

ii. Apparent depth,h 1iii.Optical density of glass block

or Refractive index of glass blockor Type of medium

1

(b) Tabulate H and h and show H as the manipulated variable and h asthe responding variable.

H/cm h/cm

2.0 1.3

3.0 2.0

4.0 2.75.0 3.3

6.0 4.0

Give one (1) mark for each of the following :1. Show column for H and h respectively.

2. State the unit for H and h correctly.

3. State the value H up to 1 d.p4. Show the reading of h correctly up to 1 d.p

5. Show consistency of all data up to 1 d.p.

5

(c) Draw a graph of h against H

Give one (1) mark for each of the following :

1. Show h at y-axis and H at x-axis.

2. State the correct unit for both axis.

3. Show uniform scale for both axis.4. Show all data plotted correctly: 5 correct 2m

3-4 correct 1m

5. Draw a smooth and best fit straight line on the graph.6. The minimum size of the graph at least 5 x 4 squares (10

cm x 8 cm) starting from the first point to the last point.

7

(d) i. State the relationship between h and H correctly.(Based on the students graph) 1


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h is directly proportional to H

TOTAL 16

Question

Number

Answer Full

Mark

2 (a)(i) Show the extrapolation on the graph1

R is directly propotional toA

11

(ii) Show on the graph R = 1.6 1

When R = 1.6 ,A

1= 0.90 mm

-2 1

Hence, A = 1.1 mm2 1

(iii) Gradient of the graph

- draw triangle on graph1

= 1.8 01.02 - 0

= 1.76 mm2

1

1

(b)(i)R =

A

l

Hence, resistivity = gradient

l

= 1.76 mm2

150 mm

= 1.17 x 10-2 mm

OR = 1.17 x 10-5

m

1

1

1

(vii) -Use small value of current to avoid the wire from

getting too hot easily/-Make sure the all the connections all the tightly

connected/

-Switch off the circuit if no reading is taken to avoidwire from getting too hot

1

TOTAL 12


12/15

Question

Number

Answer Full

Mark

3 (a) The volume of the snack pack influenced by / effected by / depends

on the atmospheric pressure of the surrounding. 1

(b) For a fixed mass and at constant temperature of a gas, its volume

will increase when the pressure decreases.

orThe volume of a gas increases when the pressure decreases.

1

(c)(i) To investigate the relationship between the volume and thepressure of a gas at fixed mass and temperature.

1

(ii) Manipulated variable :Volume of a gas, V

Responding variable :Gas pressure,P

Constant variable :Gas temperature,T / mass of a gas,m

1

1

(iii) Bourdon gauge, a syringe with volume scale and rubber tube 1

(iv)

1

(v)


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1. The piston of the syringe is pressed down slowly until the volume

of air inside is 120 cm3.

2. The pressure of the air in the syringe is read from the Bourdon

gauge.

3. The experiment is repeated with volume of air inside the syringeat 100 cm3, 80 cm3 , 60 cm3 , 40 cm3 and 20 cm3.

1

1

1

(vi) Volume , V / cm3 Pressure , P /Pa

120

100

80

60

40

20

1

(vii)1

TOTAL 12

Question

Number

Answer Full

Mark

4 (a) The strength of the magnetic field depends on the current flows in

the wire.

1

(b) The greater the magnitude of current, the stronger the magnetic

field.

1

(c) (i) To investigate the relationship between the current flows in the wire

and the strength of the magnetic field of an electromagnet.

1

Volume, V/cm3

Pressure, P/Pa


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(ii) Manipulated variable : the current in the solenoid

Responding variable : the strength of the magnetic field.

Fixed variable : number of turns of coils/the type of

core used/distance between the endof the soft iron rod and pins in

the petri dish.

.

1

1

(iii) D.C power supply, ammeter, rheostat, petri dish, retort stand with

clamp, a box of pins, soft iron rod, insulated copper wire andconnecting wires.

1

(iv) Set up the apparatus as shown in the figure.

1

(v) Start the experiment with 0.2A of current. Turn on the switch. Bringthe Petri dish of drawing pins near the lower end of the rod.

1

(vi) Count the number of pins attracted to the rod. Turn the switch offthe to allow the pins to fall back into the petri dish.

Repeat the experiment by varying the current with 0.3A, 0.4A, 0.5A

and 0,6A.

1

1

(vii)Current/A Number of pins attracted

0.2

0.30.4

0.5

0.6

1


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(viii)

1

TOTAL 12

Number of pins attracted

Current

physics answer n9 08

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