MINISTRY OF EDUCATION, SINGAPORE

in collaboration with
CAMBRIDGE INTERNATIONAL EDUCATION
General Certificate of Education Advanced Level

S
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PHYSICS9478/02
Paper 2 Structured Questions For examination from 2026
SPECIMEN PAPER 2 hours

You must answer on the question paper.

No additional materials are needed.

INSTRUCTIONS
● Answer all questions.
● Use a black or dark blue pen. You may use an HB pencil for any diagrams or graphs.
● Write your name, centre number and index number in the boxes at the top of the page.
● Write your answer to each question in the space provided.
● Do not use an erasable pen. Do not use correction fluid or tape.
● Do not write on any bar codes.
● You may use an approved calculator.

INFORMATION
● The total mark for this paper is 75.
● The number of marks for each question or part question is shown in brackets [ ].

This document has 24 pages. Any blank pages are indicated.

© Cambridge University Press & Assessment & MOE 2024 [Turn over
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Data
speed of light in free space c = 3.00 × 108 m s–1

permeability of free space µ0 = 4π × 10–7 H m–1

permittivity of free space ε0 = 8.85 × 10–12 F m–1

1
( 4 πε = 8.99 × 109 m F–1)
0

elementary charge e = 1.60 × 10–19 C

Planck constant h = 6.63 × 10–34 J s

unified atomic mass constant u = 1.66 × 10–27 kg

rest mass of electron me = 9.11 × 10–31 kg

rest mass of proton mp = 1.67 × 10–27 kg

molar gas constant R = 8.31 J K–1 mol–1

Avogadro constant NA = 6.02 × 1023 mol–1

Boltzmann constant k = 1.38 × 10–23 J K–1

gravitational constant G = 6.67 × 10–11 N m2 kg–2

acceleration of free fall g = 9.81 m s–2

Formulae
1
uniformly accelerated motion s = ut + at2
2
v 2 = u 2 + 2as

work done on / by a gas W = p ∆V

F
pressure p =
A

GM
gravitational potential φ = −
r

temperature T / K = T / °C + 273.15

1 Nm 2
pressure of an ideal gas p = 〈c 〉
3 V

3
mean translational kinetic energy of an ideal gas particle E = kT
2
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displacement of particle in s.h.m. x = x0 sin ωt

velocity of particle in s.h.m. v = v0 cos ωt = ± ω (x02 − x 2 )

electric current I = nAvq

resistors in series R = R 1 + R 2 + ...

1 1 1
resistors in parallel = + + ...
R R1 R2

1 1 1
capacitors in series = + + ...
C C1 C2

capacitors in parallel C = C 1 + C 2 + ...

1 1 Q2 1 2
energy in a capacitor U = QV = = CV
2 2 C 2

 − 
t
charging a capacitor Q = Q0 1 − e τ 

t
−
discharging a capacitor Q = Q0 e τ

RC time constant τ = RC

Q
electric potential V =
4πε 0 r

alternating current / voltage x = x0 sin ωt

µ0 I
magnetic flux density due to a long straight wire B =
2πd

µ0 N I
magnetic flux density due to a flat circular coil B =
2r

magnetic flux density due to a long solenoid B = µ0nI

h2
energy states for quantum particle in a box En = 2
n2
8mL

radioactive decay x = x0e–λt

ln 2
radioactive decay constant λ =
t1
2

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Answer all the questions in the spaces provided.

1 (a) A block is held at rest at point A on a frictionless ramp inclined at an angle θ to the horizontal,
as shown in Figure 1.1.

block

B
θ

Figure 1.1

The block is released and slides down the slope.

Data for the motion of the block as it moves from point A to point B are shown in Table 1.1.

Table 1.1

distance moved / m time taken / s

0.80 ± 0.01 0.64 ± 0.02

(i) Calculate the acceleration a of the block down the slope.

a = .................................................. m s–2 [1]

(ii) Determine the percentage uncertainty in the value of a calculated in 1(a)(i).

percentage uncertainty = ........................................................% [1]

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(iii) Use your answers in 1(a)(i) and 1(a)(ii) to determine the value of a, with its
absolute uncertainty, to an appropriate number of significant figures.

 a = ............................ ± ..................... m s–2 [2]

(iv) Show that the speed of the block at point B is 2.5 m s–1.

[1]

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(b) A barrier is now fixed at point B, as shown in Figure 1.2.

block

fixed barrier

B
θ

Figure 1.2

The block is released from rest at point A and slides down the ramp.

The block collides with the barrier at point B. The block bounces back off the barrier and
moves up the ramp with an initial speed of 1.8 m s–1.

The block has a mass of 350 g and is in contact with the barrier for a time of 0.060 s.

(i) Explain whether the collision between the block and the barrier is elastic or inelastic.

............................................................................................................................................

....................................................................................................................................... [1]

(ii) Calculate the magnitude of the average force Fav between the block and the barrier
while they are in contact.

Fav = ....................................................... N [3]

(iii) Explain whether momentum is conserved in this collision.

............................................................................................................................................

............................................................................................................................................

....................................................................................................................................... [1]

 [Total: 10]

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2 A hot air balloon contains a fixed mass of air that expands on heating, as illustrated in Figure 2.1.

2.20 “ 103 m3 2.80 “ 103 m3

105 °C

hot air balloon

heater

initial temperature final temperature

Figure 2.1

The air inside the balloon is heated to a final temperature of 105 °C and the balloon expands in
volume at atmospheric pressure from 2.20 × 103 m3 to 2.80 × 103 m3. At this final temperature,
the balloon is fully inflated.

Assume that the air inside the balloon is an ideal gas.

(a) Initially, before being heated, the air inside the balloon is in thermal equilibrium with the
material from which the balloon is made. This material is in thermal equilibrium with
the atmosphere.

(i) Calculate the initial temperature, in °C, of the air inside the balloon.

initial temperature = .......................................................°C [2]

(ii) Explain what can be deduced about the initial temperature of the atmosphere from the
zeroth law of thermodynamics.

............................................................................................................................................

............................................................................................................................................

....................................................................................................................................... [2]

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(b) During the expansion, the internal energy of air inside the balloon increases by 116 MJ.

Atmospheric pressure is 1.01 × 105 Pa.

(i) Calculate the work done on the atmosphere by the expanding balloon.

work done = ........................................................ J [1]

(ii) Use the first law of thermodynamics to determine the thermal energy supplied to the
air inside the balloon during the expansion. Explain your reasoning.

thermal energy = ........................................................ J [2]

(c) (i) State what is meant by the internal energy of a system.

............................................................................................................................................

............................................................................................................................................

....................................................................................................................................... [2]

(ii) Explain, with reference to the energy of particles, why the internal energy of the
air inside the balloon increases during the expansion.

............................................................................................................................................

............................................................................................................................................

....................................................................................................................................... [2]

 [Total: 11]

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3 (a) Two waves travelling in opposite directions in the same medium meet and superpose.

State two conditions that must be met for an observable stationary wave to be formed.

1 .................................................................................................................................................

....................................................................................................................................................

2 .................................................................................................................................................

....................................................................................................................................................
[2]

(b) Figure 3.1 shows apparatus used to demonstrate a stationary sound wave.

loudspeaker

tube
signal generator

air

water

Figure 3.1

The frequency of the sound produced by the loudspeaker is set so that a stationary wave
with the longest possible wavelength is formed in the air column in the tube.

(i) Describe the movement of the air particles at the top of the air column.

............................................................................................................................................

............................................................................................................................................

....................................................................................................................................... [2]

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(ii) On Figure 3.2, label the position of a displacement node DN and the position of a
pressure node PN.

Figure 3.2
[2]

(iii) The length of the air column is 18 cm.

The frequency of the sound emitted by the loudspeaker is 490 Hz.

Calculate the speed of sound in the air column.

speed = .................................................. m s–1 [2]

 [Total: 8]

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4 (a) Define electric field strength.

....................................................................................................................................................

............................................................................................................................................... [1]

(b) A charged metal sphere of mass 2.50 × 10–5 kg is suspended from a light, insulating thread
so that it hangs midway between two vertical metal plates, as shown in Figure 4.1.

insulating thread

metal sphere,
mass 2.50 “ 10–5 kg,
charge +4.00 nC

metal plates

Figure 4.1

The charge on the sphere is +4.00 nC.

A potential difference (p.d.) of 5.70 kV is now applied across the plates such that the
right‑hand plate is at a higher potential than the left-hand plate. The left-hand plate
is earthed.

(i) On Figure 4.2, draw a line representing the +3.80 kV equipotential due to the charged
plates only (ignoring the charged sphere). Label your line V.

– +

Figure 4.2
[2]
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(ii) The applied p.d. causes the sphere to move to a new position. The sphere does not
touch either plate.

On Figure 4.2, draw the new position of the charged sphere. [1]

(iii) The perpendicular distance between the plates is 2.00 × 10–1 m.

Calculate the electric field strength due to the applied p.d. in the region between the
plates. Include the unit with your answer.

electric field strength = .................................... unit ............... [3]

(iv) Determine the magnitude of the force exerted on the sphere by the electric field.

force = ....................................................... N [2]

(v) Use your answer in 4(b)(iv) to determine the angle to the vertical of the thread.

angle = ......................................................... ° [2]

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(c) It is found that, in practice, the actual angle of deflection of the thread in 4(b) is different from
the answer in 4(b)(v).

Suggest, with a reason, how the actual angle compares with the answer in 4(b)(v).

....................................................................................................................................................

....................................................................................................................................................

............................................................................................................................................... [2]

 [Total: 13]

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5 Two parallel wires X and Y have a separation of 0.12 m, as shown in Figure 5.1.

wire X wire Y
0.32 A 0.080 A

0.12 m

Figure 5.1

The current in wire X is 0.32 A and the current in wire Y is 0.080 A.

In both wires, the direction of the current is into the page.

(a) Determine the magnitude and direction of the resultant magnetic flux density at the midpoint
between the two wires.

Explain your reasoning.

magnitude = ............................................................. T

direction = ................................................................
 [4]

(b) Explain the direction of the magnetic force exerted on wire X by wire Y.

....................................................................................................................................................

....................................................................................................................................................

............................................................................................................................................... [2]

 [Total: 6]

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6 The orbital electron in a hydrogen atom may be thought of as being trapped in an infinite square
potential well such that the electron is confined to a region of width L, as shown in Figure 6.1.

to infinite to infinite
potential potential

zero
potential

Figure 6.1

The electron is represented by a standing wave that has wavefunction ψ given by:

ψ = A sin nkx

where x is the distance of the electron from the left-hand edge of the potential well, n is a
non‑zero integer and A and k are constants that depend on L.

(a) When n = 1, the electron is in its ground state.

(i) On Figure 6.1, draw the standing wave that represents the electron in its ground state.
[1]

(ii) Use your answer in 6(a)(i) to determine an expression for k in terms of L.

[2]

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(b) (i) State what is represented by | ψ |2.

............................................................................................................................................

....................................................................................................................................... [1]

(ii) Determine an expression for A. Show your working.

 [2]

 [Total: 6]

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7 Read the passage below and answer the questions that follow.

It has been announced that, by 2040, cars using an internal combustion engine (ICE) will be
phased out in Singapore. All new cars after 2040 will be electric vehicles (EVs). In Singapore,
a car typically travels 290 km a week. The average range of a car using an ICE is 800 km. The
average cost to refuel an ICE car is S$80.

Some drivers in Singapore have concerns about this phasing out of ICE cars. EVs are more
expensive to buy, the number of public charging points is at present very limited, the time to
charge is substantial, and there are also environmental issues such as the recycling of old
batteries. In addition, the range of an EV from one charge is not as great as the range of an
ICE car using one tank of fuel.

Many of these concerns may be resolved by supply and demand. The price of EVs will decrease
as the technology becomes more mainstream. It is predicted that, long before 2040, the cost of
owning an EV will become the same as that of owning an ICE car. Once there is a market for
public charging points, more will be installed. The number of public charging points in Singapore
should increase from about 1600 to 28 000 over the next ten years.

Table 7.1 shows data for an EV that is typical of those that are currently available on the market.

Table 7.1

battery capacity 72 kW h
range 400 km
time to accelerate 0–100 km h–1 7.6 s
total mass of EV 1685 kg
maximum output torque 395 N m

The typical EV uses a rechargeable battery that is located under the floor of the EV. The battery
is made up of an arrangement of many individual cells, and it uses a technology that is very
similar to that of batteries in laptop computers. The battery can be charged approximately
4000 times before requiring replacement. The home battery charger for the typical EV uses an
a.c. supply to provide power of 7.2 kW with an equivalent direct current of 32 A. The battery takes
10 hours to fully charge – the manufacturer describes this as a ‘charging speed’ of 40 km h–1.
When fully charged, the battery has a specific energy of 141 W h kg–1.

EVs can use regenerative braking systems to extend driving range. This is where the kinetic
energy of the EV is used to charge the battery, rather than being converted into thermal energy
by the brakes. This system is activated by the driver, so it does not automatically happen every
time the EV brakes.

One recent advance in battery technology is the use of wireless charging. A simple wireless
charger uses a 1.0 m2 pad on the ground containing a coil of wire. This is attached directly to the
a.c. electricity grid. A second coil is contained in a pad inside the EV, with the pad positioned as
close to the ground as possible. The arrangement operates in a very similar way to the way in
which a transformer works. In the future, it may be possible to have charging coils of wire built
into the road network that continuously top up the batteries in EVs.

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(a) (i) The cost of electrical energy is S$0.23 per kW h.

Calculate the ratio:

cost to travel 1.0 km in the typical EV

.
cost to travel 1.0 km in an ICE car

ratio = ........................................................... [1]

(ii) State why EVs for use in Singapore typically need to be charged less than once
per week.

............................................................................................................................................

....................................................................................................................................... [1]

(b) (i) Each individual cell in the battery of the typical EV has a maximum allowable
charging current of 2.0 A. Each cell has a maximum terminal voltage of 3.0 V when
being charged.

By considering the arrangement of cells in the battery, use the information and data
from the passage to determine the minimum number of cells in the battery of the
typical EV.

............................................................................................................................................

............................................................................................................................................

............................................................................................................................................

....................................................................................................................................... [3]

(ii) Suggest what the manufacturer means by a ‘charging speed’ of 40 km h–1.

............................................................................................................................................

....................................................................................................................................... [1]

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(iii) Suggest what is meant by a specific energy of 141 W h kg–1.

............................................................................................................................................

............................................................................................................................................

....................................................................................................................................... [1]

(iv) Determine the mass of the battery.

mass = ...................................................... kg [1]

(v) Use your answer in 7(b)(iv) to suggest a physics-based reason for the location of
the battery.

............................................................................................................................................

............................................................................................................................................

....................................................................................................................................... [1]

(c) Battery chargers sometimes need to convert a.c. into d.c.

(i) Complete Figure 7.1 using a single component to convert the a.c. input voltage into a
d.c. output voltage.

a.c. input d.c. output voltage

voltage across resistive load

Figure 7.1
[1]

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(ii) The a.c. input voltage varies sinusoidally with time and has period T.

On Figure 7.2, sketch the variation with time of the d.c. output voltage in 7(c)(i) for
two cycles of the a.c. input.

output
0 time
voltage 0 T/2 T 3T/2 2T

Figure 7.2
[2]

(d) The typical EV is travelling at a speed of 25 m s–1 when the driver activates the regenerative
braking system. The EV decelerates to rest and all its kinetic energy is used to charge
the battery.

Determine the distance, in km, that the EV can travel on this regenerated energy.

distance = ..................................................... km [3]

(e) (i) Explain why a wireless charger needs to use an a.c. voltage rather than a d.c. voltage.

............................................................................................................................................

....................................................................................................................................... [1]

(ii) Explain why the coil in the ground pad of a wireless charger and the coil in an EV need
to be as close together as possible.

............................................................................................................................................

....................................................................................................................................... [1]

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(f) Figure 7.3 shows the coil of a simple electric motor between the poles of a magnet.

coil rotates
F clockwise
N

coil d
S
l

direction of F
current I axis of
in coil rotation

Figure 7.3

The coil has length l and width d. The entire coil lies within the magnetic field. The magnetic
flux density between the poles of the magnet is B. There is a current I in the coil.

Two forces, each of magnitude F, act in opposite directions on the two sides of the coil, as
shown in Figure 7.3. This produces a torque that causes the coil to rotate.

(i) The current I in the coil is 96 A. The area of the rectangular coil in the magnetic field of
the magnet is 6.1 × 10–3 m2 and the coil contains 1200 turns.

Calculate the magnetic flux density B needed to produce the maximum output torque of
the typical EV.

B = ........................................................ T [3]

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(ii) A simple motor uses one pair of magnetic poles, as shown in Figure 7.4.

magnetic pole

coil

Figure 7.4

A more practical motor uses four pairs of magnetic poles arranged around the coil, as
shown in Figure 7.5.

magnetic pole

coil

Figure 7.5

Suggest an advantage of the arrangement shown in Figure 7.5.

............................................................................................................................................

............................................................................................................................................

....................................................................................................................................... [1]

 [Total: 21]

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