2011
Higher School Certificate
Half Yearly Examination
Physics
EXAM NUMBER
General Instructions
Total marks – 75
 Reading time – 5 minutes
This paper has two parts, Part A and Part B
 Working time – 2 hours
Part A – 20 marks
 Attempt Questions 1-20
 Allow about 35 minutes for this part
 Write using black or blue pen
 Draw diagrams using pencil
Part B – 55 marks
 Attempt Questions 21-30
 Allow about 1 hour and 25 minutes for this
part
 Board-approved calculators may be used
 Use the Data Sheet and Periodic Table
provided
 Use the multiple-choice answer sheet
provided
 Write your Centre Number and Student
Number at the top of this page and on
the multiple-choice answer sheet (page
20).
Outcomes Assessed: H1, H2, H3, H4, H5,
H6, H7, H8, H9, H10, H11, H13
MYPHY11_EXAM
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2011 YEAR 12 MID-YEAR EXAMINATION
PHYSICS
Part A – 20 marks
Attempt Questions 1-20
Allow about 35 minutes for this part
Use the multiple-choice answer sheet provided for Questions 1-20
Select the alternative A, B, C or D that best answers the question. Fill in the response oval
completely.
Sample
2 + 4 = (A) 2
(B) 6
(C) 8
(D) 9
A
B
C
D
If you think you have made a mistake, put a cross through the incorrect answer and fill in the
new answer.
A
B
C
D
If you have changed your mind and have crossed out what you consider to be the correct
answer, then indicate this by writing the word correct and drawing an arrow as follows:
correct
A
MYPHY11_EXAM
B
C
2
D
1
A student holds a bag of marbles from the end of a piece a string. Which of the
following changes in motion or position would cause a decrease in the apparent weight
of the bag of marbles?
(A) Pulling the bag so that it accelerates upwards.
(B)
Lowering the bag so that it accelerates downwards.
(C)
Changing to a location where there is a greater density in the underlying rock.
(D) No change in motion can alter the weight.
2
Alice, the student, is standing on top of a building and drops a ball over the edge. How
tall is the building if the ball dropped from rest takes 3.3 s to reach the ground?
(A) 16.2 m
(B)
26.7 m
(C)
53.4 m
(D) 106.7 m.
3
A centripetal force F acts on a rock made to undergo circular motion at the end of a
string. What is the magnitude of the new centripetal force if the speed of the rock were
to double and other factors remain unchanged?
(A) ½ F
(B)
2F
(C)
4F
(D) 8F
4
An unmanned space probe is sent out from the Earth to one of the outer planets.
According to the reference frame of the sun, what happens to the velocity of the space
probe as it is in the midway stage of the journey, about half way between the outer
planet and the sun?
(A) The space probes’ velocity is zero.
(B)
The space probes’ velocity is constant.
(C)
The space probes’ velocity is increasing.
(D) The space probes’ velocity is decreasing.
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5
Which of the following situations describes a system which involves decreasing
gravitational potential energy?
(A) A boy jumping down from a tree branch
(B)
A girl stretching a spring horizontally.
(C)
A bicyclist riding up a steep hill.
(D) A rocket rising vertically from Earth.
6
According to Newton, what happens the shape of the path traced out by a canon ball
launched from the top of a high mountain as the launch velocity is progressively
increased?
(A) The path changes from parabolic, to circular, then to linear.
(B)
The path changes from parabolic, to circular, then to elliptical.
(C)
The path is always parabolic.
(D) The path changes from parabolic to linear.
7
Which of the following did not occur as part of the Michelson Morley series of
experiments performed in the late 1800’s?
(A) One beam of light is split into two coherent beams.
(B)
Two beams of light are made to produce an interference pattern.
(C)
Beams of laser light are made to reflect using mirrors.
(D) The apparatus is turned through 90°.
8
A wire with current flowing down the page is sitting in magnetic field directed out of
the page as shown. Which of the following alternative correctly describes what occurs?
















(A) The current will accelerate down the page as it travels through the field.
(B)
The current will continue to flow with no acceleration.
(C)
The wire will experience force directed to the right of the page.
(D) The wire will experience force directed to the left of the page.
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9
Which of the following will assist in reducing the eddy currents which produce heat in
transformers?
(A) Making the transformer core from non-ferrite materials.
(B)
Increasing the primary voltage in the transformer.
(C)
Using a transformer core made of non-laminated iron.
(D) Circulating oil around the transformer windings.
10
Two long straight, parallel wires labelled X and Y sit next to each other, 1 cm apart, as
shown. The currents travel in the same direction, and X carries 3A while Y caries 5A.
What is the force per unit length experience by wire Y?
I
X
Y
(A) 3 x 10-4 N/m toward X.
(B)
3 x 10-4 N/m away from X.
(C)
1.5 x 10-4 N/m toward X.
(D) 1.5 x 10-4 N/m away from X.
11
A current of 2.5 A runs through a small 5 cm x 10 cm rectangular wire loop which is
sitting in a uniform magnetic field of 3.7 millitesla, as shown. What is the magnitude of
the total torque acting on the wire loop?
B
(A) 2.3 x 10-5 Nm.
(B)
3.8 x 10-5 Nm.
(C)
4.6 x 10-5 Nm.
(D) 9.3 x 10-4 Nm.
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12
What is the main principle employed by a functioning DC electric motor?
(A) Electromagnetic induction.
(B)
Motor effect
(C)
Eddy currents.
(D) Magnetic repulsion.
13
A mobile phone is connected to the mains supply using a transformer so as to charge its
8 V battery. Which alternative correctly represents the main energy conversions and
transformations occurring in this situation?
(A) AC electricity  DC electricity  chemical energy
(B)
DC electricity  AC electricity + heat  chemical energy
(C)
AC electricity  chemical energy + heat  AC electricity
(D) AC electricity  DC electricity + heat  chemical energy
14
A conducting rod is set up so that it sits in a magnetic field. It is connected to a power
source through a switch as shown below. When the switch is closed, what is the
direction of the force on the rod?
B
rod
(A) Up the page.
(B)
Down the page.
(C)
Into the page.
(D) Out of the page.
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15
A researcher carries out an experiment on x-ray crystallography. She observes that
monochromatic x-ray waves produce a diffraction pattern as they passes through a
crystal lattice. What occurs to the diffraction pattern as the distance between the crystal
lattice layers increases?
(A) The diffraction pattern widens as there is less bending of the x-rays.
(B)
The diffraction pattern widens as there is more bending of the x-rays.
(C)
The diffraction pattern contracts as there is less bending of the x-rays.
(D) The diffraction pattern contracts as there is more bending of the x-rays.
16
Two protons X and Y are located between two oppositely charged parallel plates as
shown. How does the magnitude of the force exerted by the electric field compare for X
and Y?
+50V
Y
X
-50V
(A) There is no force on either proton since they are stationary.
(B)
The force on proton X is greater than the force on proton Y.
(C)
The force on proton X is less than the force on proton Y.
(D) The force on proton X is equal to the force on proton Y.
17
A beam of light is incident on a photocell. What happens to the number of
photoelectrons and to the speed of the photoelectrons if the amplitude of the light is
increased?
number of photoelectrons
speed of photoelectrons
(A)
Increased
Unchanged
(B)
Reduced
Increased
(C)
Unchanged
Increased
(D)
Increased
Increased
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18
An electron gun shoots a beam of electrons into a region of crossed electric and
magnetic fields so that the beam follows a straight-line path, as shown. If the voltage
across plates PQ were to double, what would happen to the electric force on the
electrons and to the appearance of the beam?
Screen
P
















Q
19
Beam of
electrons
Electron-gun
Uniform
magnetic field
Force on electrons
Appearance of beam
(A)
F is unchanged
Beam is straight
(B)
F is ½ original
Beam bends towards P
(C)
F is 2x original
Beam bends towards P
(D)
F is 2x original
Beam bends towards Q
An electron in a semiconductor drops from a higher energy band to a lower energy
band, where there is a difference of 8.20 eV between energy levels. What is the
frequency of the released photon?
(A) 2.41 x 1014 Hz
(B)
1.98 x 1015 Hz
(C)
1.84 x 1032 Hz
(D) 1.24 x 1034 Hz
20
Which of the following correctly describes what happens when a semiconductor is
doped?
(A) Some of the atoms in the semiconductor crystal are replaced by atoms from different
elements.
(B)
The semiconductor crystal is loaded with either more electrons or less electrons.
(C)
The atoms in the semiconductor crystal are all replaced by atoms from different
elements.
(D) The atoms in the semiconductor crystal are all replaced by holes.
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2011 YEAR 12 MID-YEAR EXAMINATION
PHYSICS
Part B – 55 marks
Attempt Questions 21-30
Allow about 1 hour and 25 minutes for this part
Answer the questions in the spaces provided.
Show all relevant working in questions involving calculations.
Question 21 (7 marks)
Marks
A rock is thrown with a velocity of 22 ms-1 to the right at an angle of 40° above the
horizontal. The wind applies a constant horizontal acceleration of 2.4 ms-2 to the left to the
rock while it is in the air.
(a)
Calculate the time it takes to reach maximum height.
2
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(b) Calculate the horizontal distance which the rock travels when it achieves maximum
height.
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Question 21 continues over page
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Question 21 (continued)
Marks
(c) Describe how the shape of the rock’s path through the air differs when compared with a
situation with no horizontal force acting.
1
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(d) Explain whether Galileo’s treatment of projectile motion agrees with the situation
described above.
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2
Question 22 (5 marks)
Marks
Two geostationary satellites X and Y are in orbit around the earth, not far apart, as
shown.
(a)
Identify one suitable use for a geostationary satellite.
1
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(b) Calculate the orbital speed of a geostationary satellite given that the mass of the Earth
is 6.0 x 1024 kg.
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(c)
Describe two differences that would occur in the motion of satellite Y compared with X
if satellite Y were to loose kinetic energy.
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2
Question 23 (4 marks)
Marks
During the past century physicists have changed the metre standard because of
relativity theory.
(a)
What part of the theory of relativity theory brought about the change to the metre
standard?
1
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(b) Compare the current definition of a metre to the previous metre standard;
evaluate which is the better standard.
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Question 24 (5 marks)
Marks
An aluminium wheel attached to the axle of an electric motor is initially spinning
with a constant speed. A magnet is brought near to the spinning disc, as shown.
motor
(a)
Explain what happens to the magnetic flux through the disk and to the motion of
the disk when the magnet is brought near the disk.
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3
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(b) What will happen to the back emf in the electric motor when the magnet is brought
near to the spinning disc? Give your reasoning.
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2
Question 25 (4 marks)
Marks
A simple transformer is shown below.
(a)
Explain why a transformer has to have an AC input to function.
3
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(b) Calculate the number of turns in the secondary if there are 1200 turns on the primary
and the transformer is used to change 8 000 V to 240 V.
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1
Question 26 (5 marks)
Marks
Coil speakers are used in many devices.
(a) Describe the structure of a coil speaker.
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(b) Identify one use of coil speaker.
1
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(c)
What does the sound signal’s constantly changing frequency input do to the coil in
order to produce a sound?
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2
Question 27 (5 marks)
Marks
Describe how to perform a first-hand investigation to demonstrate the production of an
alternating current, and how the results can be made more reliable.
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5
Question 28 (6 marks)
Marks
A student carried out an experiment which involved the creation and detection of
radio waves using the set-up shown below.
Aerial
plates
Sparking
Induction
coil
(a)
Who was the first person to carry out such an experiment?
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(b) Justify the use of the induction coil and the aerial plate (capacitor plate).
1
2
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(c)
Explain how the use of semiconductor technology was able to produce improvements
to the early radios known as valve radios.
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Question 29 (6 marks)
Marks
Cathode ray tubes have led to many discoveries in science.
(a)
Describe the properties of cathode rays shown from experiments using the Maltese
cross tube in combination with a bar magnet.
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(b) Complete a labelled diagram showing a side view of the Maltese cross tube and the
rays. Assume that there is a North pole pointing into the page.
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Question 30 (8 marks)
Marks
Superconductors are becoming more important as technology develops.
(a)
Contrast the charge carriers in an ordinary metal and in a superconductor, and describe
how the charge carriers move through a bulk lattice in each case.
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(b) One possible future use of superconductors is in transmission lines. Describe an
advantage and a disadvantage of using superconducting wires.
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(c)
A press report states that a new superconductor has been found which has the property
Tc = 140 K. Draw a graph of Temperature versus resistance for this new
superconductor and label the features.
MYPHY11_EXAM
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2
Student Number
PHYSICS – MULTIPLE-CHOICE ANSWER SHEET
ATTEMPT ALL QUESTIONS
Question
MYPHY11_EXAM
1
A
B
C
D
2
A
B
C
D
3
A
B
C
D
4
A
B
C
D
5
A
B
C
D
6
A
B
C
D
7
A
B
C
D
8
A
B
C
D
9
A
B
C
D
10
A
B
C
D
11
A
B
C
D
12
A
B
C
D
13
A
B
C
D
14
A
B
C
D
15
A
B
C
D
16
A
B
C
D
17
A
B
C
D
18
A
B
C
D
19
A
B
C
D
20
A
B
C
D
20
HIGHER SCHOOL CERTIFICATE EXAMINATION
Physics
----------------------------------------------------------------------------------------------------------DATA SHEET
Charge on electron, qe
-1.602 x 10-19 C
Mass of electron, me
9.109 x 10-31 kg
Mass of neutron, mn
1.675 x 10-27 kg
Mass of proton, mp
1.673 x 10-27 kg
Speed of sound in air
340 m s-1
Earth's gravitational acceleration, g
9.8 m s-2
Speed of light, c
3.00 x 108 ms-1
Magnetic force constant,
k=


2.0 x 10-7 N A-2
Universal gravitational constant, G
6.67 x 10-11 N m2 kg-2
Mass of Earth
6.0 x 1024 kg
Planck constant, h
6.626 x 10-34 J s
Rydberg constant, R (hydrogen)
1.097 x 107 m-1
Atomic mass unit, u
1.661 x 10-27 kg
931.5 MeV/c2
I eV
1.602 x 10-19 J
Density of water, 
1.00 x 103 kg m-3
Specific heat capacity of water
4.18 x 103 J kg-1 K-1
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