Download Mock Exam 2013 Paper 2

Name
NEW SENIOR SECONDARY
Class
PHYSICS
Class number
MOCK EXAMINATION 2014
PHYSICS PAPER 2
Question-Answer Book
Time allowed: 1 hour
This paper must be answered in English
INSTRUCTIONS
(1)
Insert the information required in the space provided on
Page 1.
(2)
This paper consists of FOUR sections, Sections A, B, C
and D. Each section contains eight multiple-choice
questions and one structured question which carries
10 marks. Attempt ALL questions in any TWO sections.
(3)
Write your answers to the structured questions in the
ANSWER BOOK. For multiple-choice questions,
blacken the appropriate circle with an HB pencil. You
should mark only ONE answer for each question. If you
mark more than one answer, you will receive NO MARKS
for that question.
(4)
Graph paper and supplementary answer sheets will be
provided on request. Insert the information required, mark
the question number box on each sheet, and fasten them
with string INSIDE the Answer Book.
(5)
The Question-Answer Book and Answer Book will be
collected SEPARATELY at the end of the examination.
(6)
The diagrams in this paper are NOT necessarily drawn to
scale.
(7)
The last two pages of this Question-Answer Book contain a
list of data, formulae and relationships which you may find
useful.
(8)
No extra time will be given to candidates for inserting any
information or filling in the question number boxes after the
‘Time is up’ announcement.
Mock Exam Paper 2
1
Section A: Astronomy and Space Science
Q.1: Multiple-choice questions
1.1
The apparent paths of stars as seen by an observer looking west in the Northern Hemisphere is
shown in the figure below.
ground
Which of the following diagrams correctly shows the apparent paths of stars as observed due
south?
A
B
ground
C
ground
D
ground
ground
A
1.2
B
C
D
For an observer in the Northern Hemisphere, which of the following is/are the latitude of the
observer’s location?
(1)
The angle between the rotation axis of the Earth and the observer’s northern horizon.
(2)
The angle between the north celestial pole and the rotation axis of the Earth.
(3)
The angle between the ecliptic and the Equator.
A
(1) only
B
(2) only
C
(1) and (2) only
D
(2) and (3) only
Mock Exam Paper 2
A
2
B
C
D
1.3
One day, John receives a photo that records the retrograde motion of a planet. The sender has
traced the path of the planet and indicated its moving direction on the photo. Which side of the
photograph is the east?
S
P
R
Q
1.4
A
P
B
Q
C
R
D
S
A
B
C
D
A spacecraft S is orbiting the Earth. Which of the following would cause the gravitational
potential energy of S to decrease?
1.5
(1)
Move to a higher orbit.
(2)
Move to a lower orbit.
(3)
Move towards the surface of the Earth.
A
(1) only
B
(2) only
C
(1) and (3) only
D
(2) and (3) only
A
B
C
D
The apparent and absolute magnitudes of Barnard’s Star are 9.54 and 13.22 respectively.
Assume that the observation limit of the naked eye is 6. Which of the following statements
is/are correct?
(1)
The star can be seen by naked eye.
(2)
The star is less than 10 pc away from the Earth.
(3)
The size of the star relative to that of the Sun can be found using the given information.
A
(1) only
B
(2) only
C
(1) and (2) only
D
(2) and (3) only
Mock Exam Paper
A
3
B
C
D
Go on to the next page
1.6
A certain perfectly spherical star can be approximated by a blackbody. Which of the following
about the star is/are correct?
(1)
The intensity of the star obeys the inverse square law.
(2)
From its spectrum of radiation, we can find out what elements exist in its outer
atmosphere.
(3)
If its surface temperature increases, its blackbody radiation curve peaks at a longer
wavelength.
1.7
A
(1) only
B
(1) and (2) only
C
(2) and (3) only
D
(1), (2) and (3)
A
B
C
D
The absolute magnitudes of stars P and Q are equal. The surface temperature of star P is twice
that of star Q. Which of the following is correct?
1.8
A
The radius of star P is 4 times that of star Q.
B
The radius of star Q is 4 times that of star P.
C
The radius of star P is 16 times that of star Q.
D
The radius of star Q is 16 times that of star P.
A
B
C
D
Star X is a blue star with a radius much larger than that of the Sun. Which of the following is a
possible position of star X in the H-R diagram?
luminosity
P●
Q●
● Sun
surface
temperature
A
P
B
Q
C
R
D
S
Mock Exam Paper 2
R●
S●
A
4
B
C
D
Q.1: Structured question
Figures 1.1 and 1.2 show two photos of a star X (the biggest bright dot) taken at the same location
taken six months apart in the same year. In this period, star X shows a maximum shift in position
relative to background stars over one year. The kite-like shape in the photos outlines the constellation.
In the two photos, star X appears at slightly different locations in the sky.
X
Figure 1.1
X
Figure 1.2
(a)
Explain why star X is not at the exact same location in the two photos.
(b)
(i)
The parallax of star X measured from the photos above is 0.089". Estimate the distance of
star X from the Earth in light years.
(ii)
(2 marks)
What is the primary limitation of estimating the distance of a star from us using the
method of parallax?
(iii)
(2 marks)
(1 mark)
Suggest a reason why parallax was not discovered before the invention of the telescope.
(1 mark)
(iv)
The method of parallax is possible if we adopt the Copernican heliocentric model instead
of the Ptolemaic geocentric model. Explain.
(c)
(1 mark)
The radius and the surface temperature of star X are 1.79  1010 m and 4290 K respectively.
(i)
(ii)
Estimate the luminosity of star X in terms of L⊙ , where L⊙ is the luminosity of the
Sun (3.84  1026 W).
(2 marks)
Hence, classify star X.
(1 mark)
Mock Exam Paper
5
Go on to the next page
Section B: Atomic World
Q.2: Multiple-choice questions
2.1
A photocell is connected as shown. Monochromatic light is directed to the metal plate and a
photoelectric current is produced. The stopping potential is the potential difference across the
metal plate and the collector just enough to cease the current.
Which of the following changes to the set-up would give a smaller stopping potential?
2.2
(1)
Light of a longer wavelength is directed to the metal plate.
(2)
Light of a smaller intensity is directed to the metal plate.
(3)
A metal plate of larger work function is used in the photocell.
A
(1) only
B
(3) only
C
(1) and (2) only
D
(1) and (3) only
A
B
C
D
An object has a kinetic energy K and a de Broglie wavelength . If the object’s kinetic energy
becomes 3K while its mass is unchanged, what is the new de Broglie wavelength of the object?
A
1

9
B
1

3
1
C
3
D
A


Mock Exam Paper 2
6
B
C
D
2.3
The spectral lines produced by electron transitions from higher energy states to the second
excited state of a hydrogen atom is called the Paschen series. Which of the following gives the
highest frequency f of the spectral lines in the Paschen series?
2.4
A
hf =
13.6
eV
22
B
hf =
13.6
eV
32
C
hf =  
D
hf =  
 13.6 13.6 
 2  eV
2
2 
 3
A
B
C
D
 13.6 13.6 
 2  eV
2
3 
 4
In an experiment studying photoelectric effect, a metal surface is illuminated by electromagnetic
radiation of different frequencies. A graph showing the relationship between the maximum
kinetic energy K of the photoelectrons emitted and the frequency f of the incident light is then
obtained.
K
f
0
Which of the following gives the work function of the metal?
A
(intercept on the vertical axis)
B
h  intercept on the vertical axis
C
(intercept on the horizonatl axis)
D
e  intercept on the horizontal axis
Mock Exam Paper
A
7
B
C
D
Go on to the next page
2.5
Which of the following best explains the way that the  particles are deflected in Rutherford’s
-particle scattering experiment?
A
Most of the mass of a gold atom is concentrated in a tiny volume at the centre.
B
Electrons are unevenly distributed inside a gold atom.
C
There is gravtitional force between the  particle and the gold necleus.
D
Many electrons orbit a gold nucleus.
A
2.6
2.7
2.8
B
C
D
Which of the following nano materials has/have exactly two dimensions in nano scale?
(1)
Carbon nano tube
(2)
Zinc oxide nano wire
(3)
Silver nano particle
A
(3) only
B
(1) and (2) only
C
(1) and (3) only
D
(1), (2) and (3)
A
B
C
D
Which of the following postulates of Bohr’s model of the hydrogen atom is/are ‘quantum’?
(1)
The electron is moving around the nucleus in a circular orbit.
(2)
The total energy of the electron staying in its orbit remains unchanged.
(3)
The electron can only occupy certain discrete orbits.
A
(1) and (2) only
B
(1) and (3) only
C
(2) and (3) only
D
(1), (2) and (3)
A
B
C
D
Which of the following about transmission electron microscopes is/are correct?
(1)
Its resolving power is limited by Rayleigh criterion.
(2)
It can attain atomic resolution.
(3)
Samples may be damaged by fast-moving electrons.
A
(1) only
B
(1) and (2) only
C
(2) and (3) only
D
(1), (2) and (3)
Mock Exam Paper 2
A
8
B
C
D
Q.2: Structured question
Figure 2.1 shows the energy levels of a hydrogen atom (NOT to scale).
Energy / eV
3rd excited state
0.85
2nd excited state
?
1st excited state
?
13.6
ground state
Figure 2.1
(a)
Find the energy values (in eV) of the 1st excited state and the 2nd excited state.
(b)
The electron in a hydrogen atom absorbs a photon so that it jumps from the ground state to the
3rd excited state. Find the momentum of the photon.
(c)
(2 marks)
(3 marks)
The electron then returns to the ground state. State all possible transitions which emit visible
light photons. Given: the energy of a visible light photon ranges from 1.7 eV to
(d)
3.2 eV.
(2 marks)
Explain the formation of the absorption spectrum of an element.
(3 marks)
Mock Exam Paper
9
Go on to the next page
Section C: Energy and Use of Energy
Q.3: Multiple-choice questions
3.1
An electric hotplate and a microwave have end-use energy efficiencies of 70% and 55%
respectively. What is the difference in cost of using these two appliances to boil 2.0 kg of water
at 20 C? Each kW h of electricity costs $1.1. The specific heat capacity of water is 4200 J kg1
C1.
3.2
A
$0.02
B
$0.08
C
$0.29
D
$1.37
A
B
C
D
Surface X is 5 m away from a point source of light P and surface Y is 8 m away from P as
shown. The areas of X and Y are very small and the light from P hits the surfaces
perpendicularly. If the illuminance at X due to P is 50 lx, what is the illuminance at Y due to P?
8m
Y
P
5m
X
3.3
A
6.25 lx
B
19.5 lx
C
31.3 lx
D
128 lx
A
B
C
D
Which of the following statements about an air-conditioner is/are correct?
(1)
The cooling capacity of an air-conditioner is measured in watts.
(2)
The heat removed from a room by an air-conditioner is typically larger than the energy
consumed by the air-conditioner.
(3)
The refrigerant absorbs heat from the colder room and releases heat to the hotter outside.
A
(2) only
B
(1) and (3) only
C
(2) and (3) only
D
(1), (2) and (3)
Mock Exam Paper 2
A
10
B
C
D
3.4
An architect designs a house with four concrete walls and a concrete roof. He wants to install as
many windows as possible. The total area of the concrete part is AC and the total area of the
windows is AW. The U-value of the concrete part is 1.5 W m–2 K–1 and the average rate of heat
transfer per unit area through the windows is 150 W m2. The equivalent temperature difference
between the interior and exterior of the house envelope is 8 C. If the Overall Thermal Transfer
Value (OTTV) of the house must not exceed
24 W m–2, what is the maximum ratio of AW : AC?
3.5
3.6
A
1 : 6.8
B
1 : 10.5
C
1 : 15
D
12.5 : 1
A
B
C
D
Which of the following statements about an electric vehicle is/are correct?
(1)
It does not give out air pollutants.
(2)
Its end-use energy efficiency is higher than that of a fossil-fuel vehicle.
(3)
It has a smaller combustion engine than a fossil-fuel vehicle of a similar size.
A
(1) and (2) only
B
(1) and (3) only
C
(2) and (3) only
D
(1), (2) and (3)
A
B
C
D
The binding energy per nucleon varies with the mass number of a nuclide as shown below.
binding energy
per nucleon
Z
Y
X
mass number
If nuclear energy can be generated by the fusion of nuclide P, which of the points X, Y and Z
represent(s) the possible positions of P on the graph?
A
X only
B
Z only
C
X and Y only
D
X, Y and Z
Mock Exam Paper
A
11
B
C
D
Go on to the next page
3.7
A solar panel of area 4 m2 is placed on the ground. Its efficiency is 15%. Suppose the
atmosphere absorbs 30% of the solar power. What is the output power of the solar
panel when sunlight falls on it at an angle of 20 to the vertical? The solar constant is
1366 W m2.
sunlight
20
solar panel
3.8
A
196 W
B
231 W
C
539 W
D
611 W
A
B
C
D
The output power of a wind turbine is 160 kW when the wind speed is 8 m s1. What is the
output power of the turbine when the wind speed increases to 15 m s1? Assume that the
efficiency of the turbine remains unchanged.
A
219 kW
B
300 kW
C
563 kW
D
1055 kW
Mock Exam Paper 2
A
12
B
C
D
Q.3: Structured question
Figure 3.1 shows schematically a nuclear power plant using a pressurized water reactor. Pressurized
water circulates through the reactor pressure vessel.
reactor building
steam generator
turbine
steam
generator
control rods
sea
pressurized
water
water
reactor pressure
vessel
fuel
Figure 3.1
(a)
State TWO functions of pressurized water in the reactor.
(2 marks)
(b)
State and explain TWO safety measures in the nuclear power plant.
(2 marks)
(c)
In the reactor, 100 g of uranium-235 undergoes fission each hour. Each fission reaction releases
about 170 MeV of energy. The output power of the power plant is 600 MW. Estimate the
efficiency of the power plant.
(3 marks)
(d)
Explain why energy is given out when a heavy nuclide splits into lighter nuclides.
(2 marks)
(e)
State ONE disadvantage of nuclear power.
Mock Exam Paper
(1 mark)
13
Go on to the next page
Section D: Medical Physics
Q.4: Multiple-choice questions
4.1
Which of the following correctly compare(s) the rods and the cones in the human eye?
Rods
Cones
(1)
responsible for black and white vision
responsible for colour vision
(2)
most concentrated at the yellow spot
distributed throughout the retina but the yellow
spot
4.2
(3)
sensitive to dim light
A
(2) only
B
(3) only
C
(1) and (2) only
D
(1) and (3) only
not sensitive to dim light
A
B
C
D
Margaret is observing two light sources which emit red light of wavelength 630 nm in daytime.
The two light sources are 2 cm apart and they are 70 m from Margaret’s eyes. Assume the
diameter of the pupils of her eyes is 3 mm.
70 m
2 cm
Margaret
Which of the following statements is/are correct?
(1)
The two light sources can be resolved by Margaret’s eyes.
(2)
If the two light sources emit blue light instead of red light, they cannot be resolved by
Margaret’s eyes.
(3)
If Margaret observes the two sources at the same location at night, the two light sources
cannot be resolved by Margaret’s eyes.
A
(1) only
B
(2) only
C
(1) and (3) only
D
(2) and (3) only
Mock Exam Paper 2
A
14
B
C
D
4.3
Lucy is listening to a sound of 50 dB produced by a loudspeaker. Assume Lucy stays at the
same location. What is the increase in the sound intensity level if the power of the loudspeaker
is doubled?
4.4
A
3 dB
B
10 dB
C
30 dB
D
50 dB
A
B
C
D
The figure below shows several equal loudness curves of a person. X and Y are two different
notes on the same curve.
X
Y
Which of the following statements about the curves is/are correct?
(1)
Both X and Y have the same loudness of 60 phons.
(2)
If the sound intensity levels of X and Y are both decreased by 20 dB, the loudness of X is
lower than that of Y.
(3)
If the frequencies of X and Y are doubled while their intensities remain unchanged, the
loudness of X is lower than that of Y.
A
(1) only
B
(1) and (2) only
C
(2) and (3) only
D
(1), (2) and (3)
Mock Exam Paper
A
15
B
C
D
Go on to the next page
4.5
In an ultrasound scan, a pulse of frequency 3.5 MHz travels from soft tissue to a small volume
of unknown substance. The acoustic impedance of soft tissue is 1.63 × 106 Rayl. The intensity
reflection coefficient between soft tissue and the unknown substance is
4.42 × 10–4. What is the acoustic impedance of the unknown substance?
4.6
A
1.38 × 106 Rayl
B
1.59 × 106 Rayl
C
1.70 × 10 Rayl
D
7.78 × 106 Rayl
A
B
C
D
6
A transducer sends an ultrasound pulse towards an organ (Fig 1). The pulses reflected from
various boundaries are displayed on a CRO (Fig 2). Assume the speed of ultrasound in soft
tissues is 1580 m s–1.
organ
transducer
coupling gel
w
8 μs
Figure 1
Figure 2
What is the width w of the organ?
4.7
A
1.26 cm
B
2.53 cm
C
3.79 cm
D
4.42 cm
A
B
C
D
Artificial contrast media are sometimes used in X-ray imaging. Which of the following about an
artificial contrast medium is/are correct?
(1)
It has a high linear attenuation coefficient so that the space containing it is shown in white
on an X-ray film.
(2)
It can combine with other chemicals in our body and trace their way to the target organ.
(3)
It can highlight the target organ by reflecting X-rays.
A
(1) only
B
(1) and (2) only
C
(2) and (3) only
D
(1), (2) and (3)
Mock Exam Paper 2
A
16
B
C
D
4.8
The figure below shows the intensity I of an X-ray beam when passing through different
distances x in two media P and Q.
I
Q
P
x
Which of the following statements is/are correct?
(1)
The linear attenuation coefficient of P is higher than that of Q.
(2)
The density of P is higher than that of Q.
(3)
The half-value thickness of P is larger than that of Q.
A
(1) only
B
(1) and (2) only
C
(2) and (3) only
D
(1), (2) and (3)
Mock Exam Paper
A
17
B
C
D
Go on to the next page
Q.4: Structured question
Some radionuclides are used as tracers in medical imaging for diagnosis. A target organ which absorbs
a radionuclide appears as different shades of grey in the image produced by radionuclides. Figure 4.1
shows a thyroid scan of a patient using a chemical containing iodine-123 as the tracer.
left lobe
right lobe
Figure 4.1
(a)
The physical half-life and the biological half-life of iodine-123 are 13.2 hours and 65
days respectively. Find the effective half-life of iodine-123.
(2 marks)
(b)
Describe the working principle of radionuclide imaging.
(3 marks)
(c)
The thyroid gland absorbs iodine in the human body. It is known that the left lobe of the
patient functions normally. Determine whether his/her right lobe functions normally from
Figure 4.1. Explain your answer.
(d)
(2 marks)
Suggest TWO properties of iodine-123 which make iodine-123 a suitable tracer for
radionuclide imaging.
(e)
(2 marks)
Suggest ONE advantage of radionuclide imaging over X-ray imaging.
END OF PAPER
Mock Exam Paper 2
18
(1 mark)
List of data, formulae and relationships
Data
R = 8.31 J mol1 K1
NA = 6.02  1023 mol1
g = 9.81 m s2 (close to the Earth)
G = 6.67  1011 N m2 kg2
c = 3.00  108 m s1
e = 1.60  1019 C
me = 9.11  1031 kg
0 = 8.85  1012 C2 N1 m2
0 = 4  107 H m1
u = 1.661  1027 kg
(1 u is equivalent to 931 MeV)
AU = 1.50  1011 m
ly = 9.46  1015 m
pc = 3.09  1016 m = 3.26 ly = 206 265 AU
 = 5.67  108 W m2 K4
h = 6.63  1034 J s
molar gas constant
Avogadro constant
acceleration due to gravity
universal gravitational constant
speed of light in vacuum
charge of electron
electron rest mass
permittivity of free space
permeability of free space
atomic mass unit
astronomical unit
light year
parsec
Stefan constant
Planck constant
Rectilinear motion
For uniformly accelerated motion:
v
=
s
=
v
2
=
u + at
1
ut + at 2
2
u2 + 2as
Mathematics
Equation of a straight line
y = mx + c
Arc length
= r
Surface area of cylinder
= 2rh + 2r2
Volume of cylinder
= r2h
Surface area of sphere
= 4r2
Volume of sphere
4
= πr 3
3
For small angles, sin   tan    (in radians)
Astronomy and Space Science
Energy and Use of Energy
GMm
U =
r
P = AT4
f v λ
 
f 0 c λ0
gravitational potential energy
E
Stefan’s law
A(TH  TC )
Q
=
d
t
Doppler effect

A
illuminance

d
1
P = Av 3
2
U=
Atomic World
Medical Physics
1
2
me vmax = hf   Einstein’s photoelectric equation
2
 m e4 
1 
13 .6

En =  2  2e 2  =  2 eV
n
n 
 8h  0 

energy level equation for hydrogen
atom
h
h
= =
de Broglie formula
p mv

1.22 λ
d
1
power =
f
L = 10 log
I
I0
rate of energy transfer by conduction
thermal transmittance U-value
maximum power by wind turbine
Rayleigh criterion (resolving power)
power of a lens
intensity level (dB)
Z = c
acoustic impedance
I r ( Z 2  Z1 ) 2
=
=
intensity reflection coefficient
I 0 ( Z 2  Z1 ) 2
19

1.22 λ
d
Rayleigh criterion (resolving power)
I  I 0e x
A1.
E = mcT
energy transfer during
heating and cooling
D1.
F=
A2.
E = lm
energy transfer during
change of state
D2.
E=
A3.
pV = nRT
equation of state for an
ideal gas
D3.
A4.
pV =
1
Nmc 2
3
kinetic theory equation
A5.
EK =
3RT
2N A
molecular kinetic energy
v  p
=
t  t
transmitted intensity through a
medium
Q1Q 2
4 π 0 r 2
Q
Coulomb’s law
4π 0 r 2
electric field strength due to a
point charge
V=
Q
4π 0 r
electric potential due to a
point charge
D4.
E=
V
d
electric field between parallel
plates (numerically)
D5.
I = nAvQ
general current flow equation
D6.
R=
force
D7.
R = R1 + R2
l
resistance and resistivity
A
B1.
F =m
B2.
moment = F  d
moment of a force
D8.
B3.
EP = mgh
gravitational potential
energy
D9.
P = IV = I2R
power in a circuit
B4.
EK =
kinetic energy
D10.
F = BQv sin 
force on a moving charge in a
magnetic field
B5.
P = Fv
mechanical power
D11.
F = BIl sin 
force on a current-carrying
conductor in a magnetic field
B6.
a=
centripetal acceleration
D12.
V=
B7.
F=
Newton’s law of
gravitation
D13.
B=
D14.
B=
fringe width in
double-slit interference
D15.
=N
D16.
Vs N s

Vp N p
ratio of secondary voltage to
primary voltage in a
transformer
E1.
N = N0ekt
law of radioactive decay
E2.
t1 =
1
mv 2
2
v2
= 2r
r
Gm1 m 2
r
2
λD
a
C1.
y =
C2.
d sin  = n
diffraction grating
equation
C3.
1 1 1
 =
u v f
equation for a single
lens
1
1
1
=
+
R R1 R 2
2
BI
nQt
0 I
2 πr
 0 NI
l

t
ln 2
k
resistors in series
resistors in parallel
Hall voltage
magnetic field due to a long
straight wire
magnetic field inside a long
solenoid
induced e.m.f.
half-life and decay constant
E3.
A = kN
activity and the number of
undecayed nuclei
E4.
E = mc2
mass-energy relationship
20