1

A

B

5 kg

10 kg 15 N

St. Joseph’s Anglo-Chinese School

Mock Examination 2007/2008

Form 5 Physics Paper 2

Time allowed: 1 hour

There are 27 questions in Section A and 18 questions in Section B.

ANSWER ALL QUESTIONS. You should mark all your answers on the Answer Sheet.

You should mark only ONE answer for each question. If you mark more than one answer, you will

receive NO MARKS for that question.

The last page of this question paper contains a list of physics formulae which you may find useful.

If necessary, take g = 10 ms-2.

Unless otherwise specified, all the cells are assumed to have negligible internal resistance.

Section A

1 May slides down along a straight water slide from rest. If she accelerates at 5 m s−2 down the slide

and it takes her 3.22 s to finish the whole journey, what is the length of the slide?

A 8.05 m

B 25.9 m

C 51.8 m

D Cannot be determined.

2 Box A is placed on box B and the masses of A and B are 5 kg and 10 kg respectively.

If all surfaces are smooth, what are the accelerations of A and B when 15 N applies on B

horizontally?

Acceleration of A Acceleration of B A 1 m s−2 1 m s−2 B 0 1.5 m s−2 C 1.5 m s−2 1.5 m s−2 D 0 1 m s−2

3 Which of the following physical quantities is/are vectors?

(1) Force

(2) Work done

(3) Kinetic energy

A (1) only.

B (2) only.

C (1) and (2) only.

D (1), (2) and (3).

2

4 CN Tower in Canada is 533 m tall and it is the tallest building in the World. If a stone of 200 g is

thrown vertically upwards at 5 m s−1 at the top of the CN Tower, what is the kinetic energy of the

stone when it drops to the ground? Neglect air resistance.

A 2.5 J

B 535 J

C 1068.5 J

D 2140 J

5 A metal block of 0.2 kg and 80 °C is put in water of 1 kg and 25 °C. If the heat capacity of the

metal block is 120 J °C−1, which of the following is the final temperature of the mixture?

Assume there is no energy loss to the surroundings.

(Specific heat capacity of water = 4200 J kg−1 °C−1)

A 25.3 °C

B 26.5 °C

C 34.2 °C

D 52.5 °C

6.

Two solid substances X and Y of equal mass are separately heated by two identical heaters. The

above graph shows the variation of the temperatures of the substances with time. Which of the

following statements is/are correct?

(1) The melting point of X is higher than that of Y.

(2) The specific heat capacity of X is smaller than that of Y.

(3) The specific latent heat of fusion of X is smaller than that of Y.

A. (1) only

B. (3) only

C. (1) and (2) only

D. (2) and (3) only

7 Which of the following phenomena CANNOT be explained by conduction of heat?

A The furs and feathers of some wild animals are thickest in winter.

B The handles of saucepan are usually made of insulators of heat.

C The heating parts of the cooking utensils are made of metals.

D The heat exchanger at the back of refrigerator is painted black.

8 Which of the following processes involve(s) convection?

(1) Formation of land and sea breezes.

(2) Transfer of solar energy from the Sun to the Earth.

(3) Heating a kettle of water on a stove.

A (1) only.

B (3) only.

C (1) and (2) only.

D (1) and (3) only.

3

9 Which of the following descriptions about radiation is/are correct?

(1) Radiation requires no medium for transmission.

(2) Human bodies emit infra-red radiation.

(3) Wearing dark clothes keeps warm better than wearing light clothes in a cold day.

A (2) only.

B (1) and (2) only.

C (2) and (3) only.

D (1), (2) and (3).

10 The apparatus below is for finding the specific latent heat of fusion of ice.

Which of the following are the precautions for giving more accurate results?

(1) Insert the heater deeper into the crushed ice.

(2) Wrap the two funnels by insulating material.

(3) Start the experiment after the drip rates of the two funnels have become steady and about the

same.

A (1) and (2) only

B (1) and (3) only

C (2) and (3) only

D (1), (2) and (3)

11 A water wave travels towards the right. The diagram above shows the waveform at a certain

instant. Which of the following statements is/are correct?

(1) Particle P is moving downwards.

(2) Particle Q is moving upwards.

(3) Particle R is momentarily at rest.

A (1) only

B (3) only

C (1) and (2) only

D (2) and (3) only

4

12 A water wave of frequency 40 Hz travels in a shallow region of water. When the wave enters a

deep region, its wavelength is increased to 4 times of its original value. Find the frequency of the

water wave in the deep region.

A 10 Hz

B 40 Hz

C 160 Hz

D It cannot be determined as the speed of the water wave is not given.

13 In the following diagram, the magnification of the real image is 1.5. What is the focal length of the

convex lens?

A 4 cm

B 6 cm

C 8 cm

D 10 cm

14 A man stands facing a wall. He claps his hands and hears the echo after 2.5 s.

(The diagram is not drawn to scale.)

If the speed of sound is 340 m s−1, what is the separation between the man and the wall?

A 425 m

B 625 m

C 850 m

D 1250 m

15

In the above figure, the iron is not properly connected. Which of the following arrangements

is/are required?

(1) The fuse should be connected to wire Z instead of wire X.

(2) The switch S should be connected to wire X instead of wire Z.

(3) The wire Y should not be connected to the metal case.

A (1) only

B (2) only

C (1) and (3) only

D (2) and (3) only

wall a man claps his hand

5 cm

5

16

If the resistance of each lamp is 5 Ω and the resistance of the motor is 10 Ω, what is the total

power dissipated by the lamps and the motor?

A 11.5 W

B 12.5 W

C 15 W

D 18 W

17 An electric kettle of power 1500 W takes 15 minutes to boil 3 liters of water. If electrical energy

costs $0.85 per kW h, how much does it cost to boil water by this kettle?

A $0.05 per liter

B $0.106 per liter

C $0.212 per liter

D $0.319 per liter

18

Two magnets are arranged as shown in the above figure. Which of the following figures best

represents their magnetic field?

A

B

C

D

12 V

• •

M

5 Ω

10 Ω

5 Ω

6

19

In the figure, a copper rod is suspended horizontally by two insulating threads AB and CD, and the

direction of the magnetic field is into the paper. What happens when the switch of the circuit is

closed?

A The copper rod will move into the paper.

B The copper rod will swing into and out of the paper alternately.

C The tension in each thread is decreased.

D The tension in each thread is increased.

20

In the above figure, a radioactive source emitting α particles, β particles and γ ray is placed in

front of a sheet of paper, 5 mm aluminum and 25 mm lead. What radiation will be detected in

regions I, II and III?

I II III A α particles β particles γ rays B β particles and γ rays γ rays (no radiation)

C β particles and γ rays γ rays γ rays D α particles, β particles and

γ rays

β particles and

γ rays

γ rays

21 Which of the following statements about γ ray is/are correct?

(1) It is an electromagnetic wave of the shortest wavelength.

(2) It carries positive charges.

(3) It can never be fully absorbed.

A (1) only

B (3) only

C (1) and (3) only

D (2) and (3) only

radioactive source

paper

5 mm of aluminium

25 mm of lead

I II III

7

22 A GM tube measures the emission rate of a radioactive source. The initial reading of the GM tube

is 1500 counts per minute. After 12 hours, the reading drops to 375 counts per minute. What is the

half-life of the source?

A 3 hours

B 6 hours

C 9 hours

D 12 hours

23 ZYXW →→→βαβ

A radioactive nuclide W decays to a nuclide Z by emitting one α- and two β-particles as shown

above. Which of the following statements about nuclides W, X, Y and Z is/are correct?

(1) W and Z are isotopes.

(2) X has the greatest atomic number.

(3) Y has the greatest mass number.

A (2) only

B (3) only

C (1) and (2) only

D (2) and (3) only

24 Which of the following is / are deduced from the Rutherford’s scattering experiment?

(1) There are neutrons inside the nucleus.

(2) α particles are helium nucleus.

(3) Most of the mass is concentrated at the centre of atom.

A (3) only

B (1) and (2) only

C (2) and (3) only

D (1), (2) and (3)

25 What is the function of the control rods inside the reactor core of a nuclear power plant?

A To provide the fuel of fission.

B To slow down the speed of neutrons.

C To control the rate of nuclear reactions.

D To purify the water inside the reactor core.

26 XPHeAl +→+ 30

15

4

2

27

13

In the above nuclear reaction, what are the atomic number and mass number of X?

Atomic number Mass number

A. -1 0

B. -1 1

C. 0 1

D. 1 0

8

Directions: Each question below (question 27) consists of two statements. Decide whether each of

the two statements is true or false. If both are true, then decide whether or not the second statement is a

correct explanation of the first statement. Then select one option A, B, C, or D according to the

following table:

1st statement 2nd statement

A True True The 2nd statement is a correct explanation of the 1st statement

B True True The 2nd statement is not a correct explanation of the 1st statement.

C True False

D False True

1st statement

27 Light is a wave.

2nd statement

Light can undergo refraction when it travels from

one medium to another.

Section B

28 The following figure shows the position-time graph of the motion of a trolley in a straight line.

Which of the following statements about the motion of the trolley is/are correct?

(1) The motion of the trolley starts when time is about 1.5 s.

(2) The trolley changes its direction at about 3.4 s.

(3) The trolley returns to its original position finally.

A (1) and (2) only.

B (1) and (3) only.

C (2) and (3) only.

D (1), (2) and (3).

9

29 An object of mass 0.5 kg is pressed against a smooth wall with a force of 15 N. The force is

inclined at 30°. Find the normal reaction and the acceleration of the object.

Normal reaction Acceleration

A 7.5 N 16.0 m s–2

B 7.5 N 25.0 m s–2

C 13.0 N 5 m s–2

D 13.0 N 15 m s–2

30 Mary of weight W stands inside a lift. The life is moving downwards with uniform deceleration.

Let R be the normal reaction exerted on Mary by the floor. Which of the following statements

is/are correct?

(1) R is greater than W in magnitude.

(2) R and W are in opposite directions.

(3) R and W form an action-and-reaction pair according to Newton's third law.

A (1) only

B (2) only

C (1) and (2) only

D (2) and (3) only

31 A ball falls from a height of h to the ground and bounces back to the same height. Which of the

following statements is/are correct?

(1) The momentum of the ball just before collision and that just after collision is the same.

(2) The speed of the ball just before collision and that just after collision is the same.

(3) The net force acting on the ball during the downward journey and that during the upward

journey is same.

A (1) and (2) only

B (1) and (3) only

C (2) and (3) only

D (1), (2) and (3)

32 A 6000 kg van travelling at 90 km h−1 collides head on with another 5000 kg van, which is at rest.

If the two vans stick together and move at the same velocity after collision, what is their common

velocity?

A 11.1 m s−1

B 13.6 m s−1

C 30 m s−1

D 49.1 m s−1

30°

F = 15 N

0.5 kg

10

33 Which of the following statements about heat, internal energy and temperature of two objects

is/are correct?

(1) The object with larger internal energy must have a higher temperature.

(2) The object with particles of larger average kinetic energy must have a higher temperature.

(3) When objects are in contact, heat is transferred from the one with larger internal energy to the

other.

A (1) only.

B (2) only.

C (1) and (3) only.

D (2) and (3) only.

34 A series of sound waves travels towards a house. When the waves pass the house, they bend

around the corners of the house. Which of the following is/are correct?

(1) The phenomenon is called diffraction.

(2) The speed of the waves remains unchanged as they bend around the corners.

(3) The degree of bending of the waves depends on the size of the house relative to the

wavelength of the waves.

A (1) and (2) only

B (1) and (3) only

C (2) and (3) only

D (1), (2) and (3)

35 Which of the following cases involve total internal reflection of light?

(1)

(2)

(3)

A (1) and (2) only

B (1) and (3) only

C (2) and (3) only

D (1), (2) and (3)

image of dolphin

image of dolphin images of buildings

11

(Questions 36 – 37)

In the following figure, two loudspeakers X and Y are connected to a signal generator, and a

microphone is connected to a CRO.

When the microphone moves from P to Q, where P lies on the perpendicular bisector of X and Y, the

intensity of the sound detected is shown in the following figure.

36 If the frequency of the signal generator is set at 850 Hz, and the speed of sound is 340 m s–1, what

is the path difference between XQ and YQ?

A 0.5 m

B 0.75 m

C 1 m

D 1.5 m

37 Which of the following figures best shows the display of CRO when the frequency is doubled?

A B

C D

Intensity

12

A B

resistor

38 Which of the following statements about electric field lines is/are correct?

(1) All electric field lines are curved.

(2) No electric field line intercepts with other electric field lines.

(3) The direction of field lines shows the direction of the electric force experienced by an

electron placed in the field.

A (1) only

B (2) only

C (1) and (3) only

D (2) and (3) only

39

In the above circuit, all the light bulbs are identical. What happens to the brightness of the bulbs

L1, L2 and L3 if switch S is closed?

L1 L2 L3

A decreases increases remains unchanged

B decreases remains unchanged remains unchanged

C remains unchanged decreases increases

D increases remains unchanged increases

40 Which of the following statements about the following set-up is/are correct?

(1) The voltage produced by the generator can be increased by rotating the coil at a higher speed.

(2) The voltage produced by the generator can be increased by replacing the coil with one of

larger area.

(3) Current passes through the resistor from A to B.

A (1) and (2) only

B (1) and (3) only

C (2) and (3) only

D (1), (2) and (3)

13

41

In the above circuit diagram, the transformer is 100% efficient. What is the maximum number of

identical light bulbs, each of rating “40 W, 10 V” that can be connected in parallel across the

secondary coil without blowing the fuse? (Assume that the fuse will blow if the current flowing

through it exceeds 15 A.)

A 2

B 20

C 60

D 75

42

Two coils of conducting wires are wound on a soft-iron core as shown above. Switch S is closed

and after a while re-opened. Which of the following statements is/are correct?

(1) At the moment when S is closed, a current flows through R from P to Q.

(2) When S remains closed, there is no current flowing through R.

(3) At the moment when S is re-opened, a current flows through R from P to Q.

A (1) only

B (3) only

C (1) and (2) only

D (2) and (3) only

43 100 kW of electrical power is transmitted at 20 kV through cables of total resistance 4 Ω. Find the

voltage drop and power loss in the cables.

Voltage drop Power loss

A 20 V 100 W

B 100 V 20 W

C 100 V 100 W

D 20 kV 100 kW

14

Directions: Each question below (questions 44 – 45) consists of two statements. Decide whether

each of the two statements is true or false. If both are true, then decide whether or not

the second statement is a correct explanation of the first statement. Then select one

option A, B, C, or D according to the following table:

1st statement 2nd statement

A True True The 2nd statement is a correct explanation of the 1st statement

B True True The 2nd statement is not a correct explanation of the 1st statement.

C True False

D False True

1st statement

44 The efficiency of a transformer can be

increased by increasing the number of turns

of the secondary coil.

45 An ammeter should have a low resistance.

2nd statement

The secondary voltage of transformer can be

increased by increasing the number of turns of

the secondary coil.

An ammeter of high resistance significantly

reduces the current in the circuit to which it is

connected.

Useful Formulae in Physics

(a) Relationships between initial velocity u, uniform acceleration a, final velocity v and displacement

travelled s after time t:

v = u + at s = ut +1

2at2 v2 = u2 + 2as

(b) Potential energy gained by a body of mass m when raised through a height h is mgh.

(c) Kinetic energy of a body of mass m moving with speed v is 1

2mv2.

(d) Power = force × velocity

(e) Equivalent resistance of two resistors R1 and R2:

(i) in series = R1 + R2

(ii) in parallel = 21

21

RR

RR

+

(f) Power = voltage × current

--- End of Paper --

15

St. Joseph’s Anglo-Chinese School

Mock Examination 2007/2008

Form 5 Physics Paper 2

Answers

1 B 11 D 21 C 31 C 41 D

2 B 12 B 22 B 32 B 42 C

3 A 13 B 23 C 33 B 43 A

4 C 14 A 24 A 34 D 44 D

5 B 15 B 25 C 35 A 45 A

6 D 16 A 26 C 36 C

7 D 17 B 27 B 37 D

8 D 18 C 28 D 38 B

9 D 19 C 29 C 39 A

10 B 20 C 30 C 40 A

1. By s = ut + ½ at2

The length of the slide = (0)(3.22) + ½ (5)(3.22)2 = 25.9 m

2. No horizontal force acts on block A ⇒ acceleration of A = 0 ms-2

15 N is the only horizontal force acting on box B ⇒ Acceleration of B = 15 / 10 = 1.5 ms-2

5. Assume there is no energy loss to the surroundings.

Energy gained by water = Energy lost by the metal block

(1)(4200)(T – 25) = 120(80 – T)

T = 26.5oC

Note: heat capacity = mass x specific heat capacity

12. The frequency of water waves remains unchanged when the waves enter a deep region.

14 2d = 340 x 2.5

d = 425 m

∴ The separation between the man and the wall = 425 m.

16. Total resistance in the circuit = 5.1210

5

1

5

1

1=+

+

Ω

Current through the motor = 12 / 12.5 = 0.96 A

Total power dissipated by the lamps and the motor = total power = VI = (12)(0.96) = 11.52 W

16

19

By Fleming’s left hand rule, the magnetic force acting on the copper rod is pointing upward.

Hence, the tension in each thread is decreased.

22 final reading / initial reading = 375 / 1500 = 1/4 = (½)2

12 hours = 2 half-life

∴ the half-life of the source is 6 hours

29

In horizontal direction: R = 15 cos 30o ⇒ R = 13.0 N

In vertical direction: 15sin 30o – 5 = 0.5a ⇒ a = 5 ms-2

30 The life is moving downwards with uniform deceleration.

(1) R is greater than W in magnitude. (correct)

(2) R and W are in opposite directions. (correct)

(3) R and W form an action-and-reaction pair according to Newton's third law. (incorrect)

Because R and W are both acting on Mary while action and reaction act on different bodies.

33 (1) The object with larger internal energy must have a higher temperature. (incorrect)

Reason: Internal energy is the sum of potential energy and kinetic energy of all particles in an

object. If the mass of an object is large, the internal energy will be large but the

temperature can be low.

(3) When objects are in contact, heat is transferred from the one with larger internal energy to the

other. (incorrect)

Reason: Heat is transferred from the one with higher temperature to the other.

current

magnetic force

30°

F = 15 N

0.5 kg

W = 5 N

R

17

36 By v = fλ

340 = 850λ

λ = 0.4 m

Path difference between XQ and YQ = 2.5 λ = 2.5 x 0.4 = 1 m

37 If the frequency is doubled, the wavelength decreases by half. The path difference between XQ

and YQ = 5λ’ where λ’ is the new wavelength. Hence, constructive interference occurs at Q and Q

is at the 6th peak of the graph.

39. Let V be the voltage of the cells.

When the switch is closed,

L1 is shorted ⇒ brightness of L1 decreases

Voltage across L2 increases from V/2 to V ⇒ brightness of L2 increases

Voltage across L3 remains unchanged ⇒ brightness of L3 remains unchanged

41 Maximum current allowed to flow through the fuse = 15 A

⇒ maximum power input = 200 x 15 = 3000 W

Since the transformer is 100 % efficient, maximum power output = 3000 W

Maximum number of bulbs = 3000 / 40 = 75

43 Current through the cable = 100 k W / 20 k V = 5 A

Voltage drop = IR = (4)(5) = 20 V

Power loss = I2R = (5)2(4) = 100 W