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物理代写-MUF0122
时间：2021-10-30
Monash University Foundation Year
TOTAL MARKS: [ ]
(Marker Use Only)
MUF0122 Physics Unit 2 Sample Examination
Reading time: 10 minutes | Writing time: 80 minutes
QUESTION & ANSWER BOOKLET
Structure of Examination
Section Type of question(s) Number of questions
Number of
questions to be
answered
Number of
marks
A Multiple-choice Questions 10 10 20
B Short-answer Questions 17 17 60
Total Marks 80
Instructions
Answer all questions
Section A questions must be answered on the Multiple-choice Answer Sheet provided on page 20. This
may be removed. Please fill in your details at the top of the page and place the completed Multiple-
choice Answer Sheet behind the front cover of this booklet.
Section B questions should be answered in the spaces provided in this Booklet.
• Show all working for questions worth multiple marks
• Answer should be given in scientific notation to the correct number of significant figures
Data sheets (pages 18 and 19) have been provided.
Throughout the paper use g = 9.81 m s-2 for the acceleration due to gravity at the earth’s surface.
Candidates must write clearly and in English.
Materials allowed:
• A non-programmable calculator (memory cleared) is allowed.
Candidates are to fill in the following. Do not write your name or your lecturer’s/teacher’s name on your
examination booklet(s).
Student ID Number:
Desk number:
Campus Location:
For Marker Use Only
A
MC
B
Q1
B
Q2
B
Q3
B
Q4
B
Q5
B
Q6
B
Q7
B
Q8
B
Q9
B
Q10
B
Q11
B
Q12
B
Q13
B
Q14
B
Q15
B
Q16
B
Q17
Total
Marker /20 /5 /4 /5 /3 /3 /6 /3 /3 /2 /6 /2 /2 /2 /2 /5 /4 /3 /80
Moderator
Examiner
Page 2 of 20
SECTION A – Multiple-choice questions
Instructions for Section A
Answer all questions on the Multiple-choice Answer Sheet on page 20.
Choose the response that best answers the question or completes the statement.
A correct answer scores 2; an incorrect answer scores 0.
No marks will be awarded if more than one letter is circled for any question.
Unless otherwise indicated, the diagrams are not drawn to scale.
You should spend approximately 20 minutes on this section.
Question 1
A child has glow-in-the-dark stickers on her bedroom ceiling that absorb energy when the light in the room
is on. They can be seen when the room is darkened because they
A. reflect light.
B. transmit light.
C. emit light.
D. absorb light.
Question 2
Infra Red (IR) and Ultra Violet (UV) are both categories of electromagnetic radiation. Which of the following
statements is false?
A. IR has a longer wavelength an UV.
B. UV travels faster in air than IR.
C. UV is more energetic than IR.
D. Both IR and UV undergo diffraction when passing through narrow gaps.
Question 3
White light is shone into the end of a long length of optical fibre. With some laboratory equipment, a physics
student finds that at the other end of the fibre, red light was emitted first, then other colours, and lastly,
violet coloured light was emitted. This is due to
A. refraction.
B. reflection.
C. diffraction.
D. dispersion.
Page 3 of 20
Question 4
The ‘pitch’ of a musical note is due to its
A. amplitude.
B. loudness.
C. frequency.
D. speed.
Question 5
A stationary charged particle produces
A. a negative charge.
B. a positive charge.
C. a magnetic field.
D. an electric field.
Question 6
Two charges have an electrostatic force of F newton between them. Both charges are doubled in size, and
the distance between them is also doubled. The force between them is now
A. F newton.
B. 2F newton.
C. 4F newton.
D. 8F newton.
Question 7
In a series circuit, which of the following is not true?
A. The current is the same in each element.
B. The potential difference across each element is always the same.
C. The power output of the circuit is the sum of the power output of each element.
D. The total resistance is the sum of the resistance of each resistance.
Page 4 of 20
Question 8
A step-up transformer
A. increases the voltage and decreases the current.
B. increases the current and decreases the voltage.
C. increases both the voltage and the current.
D. has poor efficiency.
Question 9
A radioactive source emits one type of radiation only. On investigation, it is found that the rays will penetrate
a sheet of aluminium, but will not penetrate 1 cm of lead. The radiation emitted will most likely be
A. beta particles.
B. alpha particles.
C. X rays.
D. gamma rays.
Question 10
The photoelectric effect is evidence that
A. light exhibits wave behaviour.
B. light exhibits particle behaviour.
C. light is neither a wave nor a particle.
D. it is too difficult to model light due to its duality.
END OF SECTION A
Page 5 of 20
SECTION B – Short Answer questions
Instructions for Section B
Answer all questions in the spaces provided. If you wish to change an answer then cross it out and write
the new answer beside it.
Numerical answers should be given in standard form and with the correct number of significant figures.
The marks allocated for each sub question are indicated beside/below the question. No marks will be
deducted for incorrect responses.
In questions allocated more than 1 mark, appropriate working must be shown.
You should spend approximately 60 minutes on this section.
Use g = 9.81 m s-2 for the acceleration due to gravity at the earth’s surface.
Question 1 (Total 5 marks)
A section of optical fibre is shown below. The refractive index of the core and cladding are 1.5 and 1.4
respectively.
a. Calculate the speed of light in the core. (2 marks)
b. Determine the critical angle at the core-cladding interface. (2 mark)
c. Describe one condition required for light to be transmitted within optical fibre. (1 mark)
ncladding=1.4
ncore=1.5
Page 6 of 20
Question 2 (Total 4 marks)
A small object with height 2.0 cm is placed at a position 21 cm in front of a converging lens with a focal
length of 8.0 cm. This produces an image. A representation of this situation is shown below.
a. Calculate the distance of the image using the lens formula. (2 marks)
b. Determine the height of the image. (2 mark)
Page 7 of 20
Question 3 (Total 5 marks)
Green light of wavelength 540 nm passes through two parallel narrow slits that are 1.0 mm apart. A pattern
of alternating light and dark bands are produced on a distant screen.
a. If the green light was changed to red light of wavelength 690 nm, describe the effect this has on the
pattern. (1 mark)
b. With the original green light, if the narrow slits are moved to be 1.5 mm apart, describe the effect that
this has on the pattern. (1 mark)
c. Explain how the light and dark bands are formed AND how this supports the wave model for light.
(3 marks)
Page 8 of 20
Question 4 (Total 3 marks)
A wave with a position graph shown below is travelling at 20.0 m s-1. Both axes scales are in metre.
a. Determine the wavelength of this wave. (1 mark)
b. Calculate the frequency of this wave. (1 mark)
c. This type of wave is transverse / longitudinal (circle the correct answer) (1 mark)
Page 9 of 20
Question 5 (Total 3 marks)
A student is conducting an experiment on sound and connects a speaker to a signal generator to produce a
tone. With a sound level meter, she records a sound level of 5.0 × 10−5 W m-2 when she is 2.0 m away from
the speaker.
a. What is the sound intensity level? (2 marks)
b. She now moves the meter to a point where the sound intensity is a quarter of the initial value. How far
from the speaker is she now? (1 mark)
Page 10 of 20
Question 6 (Total 6 marks)
The flute is a musical instrument that can be modelled as a pipe,
open at both ends. The instrument is used to play a note and the
sound it produced was analysed. The sound included the following
frequencies: 780 Hz, 1300 Hz and 1560 Hz.
a. Determine the largest possible fundamental frequency. (1 mark)
b. Taking the speed of sound in air to be 340 m s-1, calculate the wavelength of the fundamental frequency.
(1 mark)
c. Draw the displacement variation of a fundamental frequency wave below, labelling maximum and
minimum displacement regions. (2 marks)
d. Now draw a pressure variation graph for the wave drawn in c, labelling maximum and minimum pressure
regions. (2 marks)
Page 11 of 20
Question 7 (Total 3 marks)
A small positively charged sphere with a charge of +8.00 × 10−8 C, and a small negatively charged sphere
with a charge of − 4.00 × 10−9 C are placed 1.00 m apart.
Another small sphere with a charge of +8.00 × 10−8 C is placed at point A, 1.00 m from the negative charge
as shown.
What is the magnitude and direction of the force on the object at A? (3 marks)
Page 12 of 20
Question 8 (Total 3 marks)
The voltage-current characteristics for two devices are shown in the graph below.
The devices are connected in parallel and connected to a power supply of 4.0 V.
State which device is ohmic and non-ohmic, the current through each device and the resistance of each
device by completing the following table. (3 marks)
Device Ohmic/Non-ohmic Current in device Resistance of device
A
B
Question 9 (Total 2 marks)
Which type of meter would be placed in each of the positions in the following circuit to measure the
resistance of the unknown device?
M1 is a/an ____________________
M2 is a/an ____________________
0
1
2
3
4
5
6
0 2 4 6 8 10 12
Cu
rr
en
t (
am
p)
Voltage (volt)
Voltage - current graph
device A
device B
Page 13 of 20
Question 10 (Total 6 marks)
The following electrical circuit is assembled in an experiment.
a. With switch S1 open, calculate the effective resistance of the circuit. (2 marks)
b. Determine the power dissipated in each of the 16 Ω resistors. (3 marks)
c. When switch S1 is closed, does the power delivered to the circuit increase or decrease? (1 mark)
Page 14 of 20
Question 11 (Total 2 marks)
A magnetic field of 0.50 tesla is produced by an electromagnet. A small coil of wire containing 100 turns is
placed within this field. The area of the loop of wire is 5.0 cm2 and it is placed perpendicularly to the field.
The coil is quickly removed from the magnetic field in 0.10 seconds.
What is the magnitude of the average induced voltage in the loop? (2 marks)
Question 12 (Total 2 marks)
A transformer is considered for use in the following situation. The globe glows brightly as it draws 1.0 ampere.
From this information, calculate the current drawn by the primary coil of the transformer. (2 marks)
Question 13 (Total 2 marks)
An unstable isotope of the element bismuth 83214 undergoes alpha decay. During this process the nucleus
of bismuth changes. Describe the change that the nucleus goes through in terms of the number of protons
and neutrons. (2 marks)
Page 15 of 20
Question 14 (Total 2 marks)
Technetium-99 is commonly used in nuclear medicine for obtaining images of internal organs of the body.
This radioisotope has a half-life of 6 hours. If a sample of 2048 mg of this radioisotope is obtained to be
used, how much technetium-99 would be remaining after 2 days? (2 marks)
Question 15 (Total 5 marks)
The diagram below shows the absorption spectra of an atom which consists of the wavelengths 485 nm (n=2)
and 325 nm (n=3). Assume the electron was initially at the ground state (n=1).
a. Calculate the energy of the level E2 in eV. (2 marks)
b. On the diagram, show the three emission transitions that are possible. (1 mark)
c. Calculate the two highest frequencies which will be seen in the atom’s emission spectrum. (2 marks)
Page 16 of 20
Question 16 (Total 4 marks)
The apparatus in the diagram below is used to investigate the photoelectric effect. Light of wavelength 253
nm ejects photoelectrons from a silver plate. The applied voltage can be varied to prevent photoelectrons
from crossing to the collector electrode.
The work function of the silver surface is 4.70 eV.
a. Determine the maximum kinetic energy (in eV) of the photoelectrons ejected from the silver plate.
(2 marks)
b. Determine the magnitude of the minimum stopping voltage that would be required to prevent the most
energetic photoelectrons from reaching the collector electrode. (1 mark)
c. Calculate the cut-off frequency for the silver surface. (1 mark)
Page 17 of 20
Question 17 (Total 3 marks)
Consider three particles A, B, and C. The masses of these particles are such that:
> >
All three particles have the same momentum. Compare their:
a. Speeds. (1 mark)
b. de Broglie wavelengths. (1 mark)
c. Kinetic energies. (1 mark)
END OF SECTION B
Page 18 of 20
Examination formula and constants
Waves
universal wave equation = =
frequency and period = 1
Snell’s law 11 = 22
Critical angle sin = 21 ,ℎ 2 ≤ 1
Reflection ∠ = ∠
refractive index = ℎ
ℎ ℎ
Speed of light in a vacuum 3.00 × 108 −1 or 300 000 kms−1
Lens formula 1
+ 1
= 1
Magnification = −�
�
Diffraction ∝
ℎ
Young’s slit Δ =
Sound intensity =
, (:−2) ∗ : = 42
Sound Intensity Level (dB) = 10 log �
� ,ℎ = 1.00 × 10−12 Wm−2
String fixed at both ends = 2 = 2
Pipe (Open-open) = 2, , 2
3
, … = , 2 , 3 , …
Pipe (Open-closed) = 4 , 4
3
, 4
5
, … = , 3 , 5 , …
Fields
Electric field between charged
plates =
Field of a point charge =
2
Coulomb’s law = 122 = 8.99 × 109 N m2 C−2
Force on an electric charge =
Energy = = Δ = Δ
Charge of the electron = −1.60 × 10−19 C
Page 19 of 20
Electricity and Magnetism
Current =
Power =
=
= = 2
= 2 ( )
Resistivity =
Ohm’s law ℎ′ → =
=
Combining resistors
() = 1 + 2 + 3 + ⋯
1
() = 11 + 12 + 13 + ⋯
Internal resistance of a battery = −
Magnetic flux Φ = sin
Magnetism = sin (); = sin (); Φ = ; = −ΔΦ
Δ
Faraday + Lenz laws = −ΔΦ
Δ
Alternating current = √2 = √2 = 2
Ideal transformer = = = = →
Modern physics
de Broglie wavelength = ℎ
= ℎ
photon: = ℎ = ℎ
Photoelectric effect = ℎ −
Photon energy = ℎ
Photon momentum = ℎ
De Broglie wavelength = ℎ
Fundamental constants:
Electric charge = −1.60 × 10−19 C
Electron rest mass = 9.11 × 10−31 kg
Proton rest mass = 1.67 × 10−27 kg
Planck’s constant ℎ = 6.63 × 10−34 Js ℎ = 4.14 × 10−15 eVs
Page 20 of 20
MUF0122 Physics Unit 2 Sample
MULTIPLE-CHOICE ANSWER SHEET
Candidates are to fill in the following. Do not write your name or your lecturer’s/teacher’s name on your
examination booklet(s).
Student ID Number:
Desk number:
Campus Location:
Instructions
Indicate your chosen answer by circling the appropriate letter like this:
• Example: A B C D
If you change your mind, clearly cross out your first response and circle your new selection.
• Example: A B C D
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
MCQ TOTAL: /20
(Marker Use Only)
学霸联盟
学霸联盟
TOTAL MARKS: [ ]
(Marker Use Only)
MUF0122 Physics Unit 2 Sample Examination
Reading time: 10 minutes | Writing time: 80 minutes
QUESTION & ANSWER BOOKLET
Structure of Examination
Section Type of question(s) Number of questions
Number of
questions to be
answered
Number of
marks
A Multiple-choice Questions 10 10 20
B Short-answer Questions 17 17 60
Total Marks 80
Instructions
Answer all questions
Section A questions must be answered on the Multiple-choice Answer Sheet provided on page 20. This
may be removed. Please fill in your details at the top of the page and place the completed Multiple-
choice Answer Sheet behind the front cover of this booklet.
Section B questions should be answered in the spaces provided in this Booklet.
• Show all working for questions worth multiple marks
• Answer should be given in scientific notation to the correct number of significant figures
Data sheets (pages 18 and 19) have been provided.
Throughout the paper use g = 9.81 m s-2 for the acceleration due to gravity at the earth’s surface.
Candidates must write clearly and in English.
Materials allowed:
• A non-programmable calculator (memory cleared) is allowed.
Candidates are to fill in the following. Do not write your name or your lecturer’s/teacher’s name on your
examination booklet(s).
Student ID Number:
Desk number:
Campus Location:
For Marker Use Only
A
MC
B
Q1
B
Q2
B
Q3
B
Q4
B
Q5
B
Q6
B
Q7
B
Q8
B
Q9
B
Q10
B
Q11
B
Q12
B
Q13
B
Q14
B
Q15
B
Q16
B
Q17
Total
Marker /20 /5 /4 /5 /3 /3 /6 /3 /3 /2 /6 /2 /2 /2 /2 /5 /4 /3 /80
Moderator
Examiner
Page 2 of 20
SECTION A – Multiple-choice questions
Instructions for Section A
Answer all questions on the Multiple-choice Answer Sheet on page 20.
Choose the response that best answers the question or completes the statement.
A correct answer scores 2; an incorrect answer scores 0.
No marks will be awarded if more than one letter is circled for any question.
Unless otherwise indicated, the diagrams are not drawn to scale.
You should spend approximately 20 minutes on this section.
Question 1
A child has glow-in-the-dark stickers on her bedroom ceiling that absorb energy when the light in the room
is on. They can be seen when the room is darkened because they
A. reflect light.
B. transmit light.
C. emit light.
D. absorb light.
Question 2
Infra Red (IR) and Ultra Violet (UV) are both categories of electromagnetic radiation. Which of the following
statements is false?
A. IR has a longer wavelength an UV.
B. UV travels faster in air than IR.
C. UV is more energetic than IR.
D. Both IR and UV undergo diffraction when passing through narrow gaps.
Question 3
White light is shone into the end of a long length of optical fibre. With some laboratory equipment, a physics
student finds that at the other end of the fibre, red light was emitted first, then other colours, and lastly,
violet coloured light was emitted. This is due to
A. refraction.
B. reflection.
C. diffraction.
D. dispersion.
Page 3 of 20
Question 4
The ‘pitch’ of a musical note is due to its
A. amplitude.
B. loudness.
C. frequency.
D. speed.
Question 5
A stationary charged particle produces
A. a negative charge.
B. a positive charge.
C. a magnetic field.
D. an electric field.
Question 6
Two charges have an electrostatic force of F newton between them. Both charges are doubled in size, and
the distance between them is also doubled. The force between them is now
A. F newton.
B. 2F newton.
C. 4F newton.
D. 8F newton.
Question 7
In a series circuit, which of the following is not true?
A. The current is the same in each element.
B. The potential difference across each element is always the same.
C. The power output of the circuit is the sum of the power output of each element.
D. The total resistance is the sum of the resistance of each resistance.
Page 4 of 20
Question 8
A step-up transformer
A. increases the voltage and decreases the current.
B. increases the current and decreases the voltage.
C. increases both the voltage and the current.
D. has poor efficiency.
Question 9
A radioactive source emits one type of radiation only. On investigation, it is found that the rays will penetrate
a sheet of aluminium, but will not penetrate 1 cm of lead. The radiation emitted will most likely be
A. beta particles.
B. alpha particles.
C. X rays.
D. gamma rays.
Question 10
The photoelectric effect is evidence that
A. light exhibits wave behaviour.
B. light exhibits particle behaviour.
C. light is neither a wave nor a particle.
D. it is too difficult to model light due to its duality.
END OF SECTION A
Page 5 of 20
SECTION B – Short Answer questions
Instructions for Section B
Answer all questions in the spaces provided. If you wish to change an answer then cross it out and write
the new answer beside it.
Numerical answers should be given in standard form and with the correct number of significant figures.
The marks allocated for each sub question are indicated beside/below the question. No marks will be
deducted for incorrect responses.
In questions allocated more than 1 mark, appropriate working must be shown.
You should spend approximately 60 minutes on this section.
Use g = 9.81 m s-2 for the acceleration due to gravity at the earth’s surface.
Question 1 (Total 5 marks)
A section of optical fibre is shown below. The refractive index of the core and cladding are 1.5 and 1.4
respectively.
a. Calculate the speed of light in the core. (2 marks)
b. Determine the critical angle at the core-cladding interface. (2 mark)
c. Describe one condition required for light to be transmitted within optical fibre. (1 mark)
ncladding=1.4
ncore=1.5
Page 6 of 20
Question 2 (Total 4 marks)
A small object with height 2.0 cm is placed at a position 21 cm in front of a converging lens with a focal
length of 8.0 cm. This produces an image. A representation of this situation is shown below.
a. Calculate the distance of the image using the lens formula. (2 marks)
b. Determine the height of the image. (2 mark)
Page 7 of 20
Question 3 (Total 5 marks)
Green light of wavelength 540 nm passes through two parallel narrow slits that are 1.0 mm apart. A pattern
of alternating light and dark bands are produced on a distant screen.
a. If the green light was changed to red light of wavelength 690 nm, describe the effect this has on the
pattern. (1 mark)
b. With the original green light, if the narrow slits are moved to be 1.5 mm apart, describe the effect that
this has on the pattern. (1 mark)
c. Explain how the light and dark bands are formed AND how this supports the wave model for light.
(3 marks)
Page 8 of 20
Question 4 (Total 3 marks)
A wave with a position graph shown below is travelling at 20.0 m s-1. Both axes scales are in metre.
a. Determine the wavelength of this wave. (1 mark)
b. Calculate the frequency of this wave. (1 mark)
c. This type of wave is transverse / longitudinal (circle the correct answer) (1 mark)
Page 9 of 20
Question 5 (Total 3 marks)
A student is conducting an experiment on sound and connects a speaker to a signal generator to produce a
tone. With a sound level meter, she records a sound level of 5.0 × 10−5 W m-2 when she is 2.0 m away from
the speaker.
a. What is the sound intensity level? (2 marks)
b. She now moves the meter to a point where the sound intensity is a quarter of the initial value. How far
from the speaker is she now? (1 mark)
Page 10 of 20
Question 6 (Total 6 marks)
The flute is a musical instrument that can be modelled as a pipe,
open at both ends. The instrument is used to play a note and the
sound it produced was analysed. The sound included the following
frequencies: 780 Hz, 1300 Hz and 1560 Hz.
a. Determine the largest possible fundamental frequency. (1 mark)
b. Taking the speed of sound in air to be 340 m s-1, calculate the wavelength of the fundamental frequency.
(1 mark)
c. Draw the displacement variation of a fundamental frequency wave below, labelling maximum and
minimum displacement regions. (2 marks)
d. Now draw a pressure variation graph for the wave drawn in c, labelling maximum and minimum pressure
regions. (2 marks)
Page 11 of 20
Question 7 (Total 3 marks)
A small positively charged sphere with a charge of +8.00 × 10−8 C, and a small negatively charged sphere
with a charge of − 4.00 × 10−9 C are placed 1.00 m apart.
Another small sphere with a charge of +8.00 × 10−8 C is placed at point A, 1.00 m from the negative charge
as shown.
What is the magnitude and direction of the force on the object at A? (3 marks)
Page 12 of 20
Question 8 (Total 3 marks)
The voltage-current characteristics for two devices are shown in the graph below.
The devices are connected in parallel and connected to a power supply of 4.0 V.
State which device is ohmic and non-ohmic, the current through each device and the resistance of each
device by completing the following table. (3 marks)
Device Ohmic/Non-ohmic Current in device Resistance of device
A
B
Question 9 (Total 2 marks)
Which type of meter would be placed in each of the positions in the following circuit to measure the
resistance of the unknown device?
M1 is a/an ____________________
M2 is a/an ____________________
0
1
2
3
4
5
6
0 2 4 6 8 10 12
Cu
rr
en
t (
am
p)
Voltage (volt)
Voltage - current graph
device A
device B
Page 13 of 20
Question 10 (Total 6 marks)
The following electrical circuit is assembled in an experiment.
a. With switch S1 open, calculate the effective resistance of the circuit. (2 marks)
b. Determine the power dissipated in each of the 16 Ω resistors. (3 marks)
c. When switch S1 is closed, does the power delivered to the circuit increase or decrease? (1 mark)
Page 14 of 20
Question 11 (Total 2 marks)
A magnetic field of 0.50 tesla is produced by an electromagnet. A small coil of wire containing 100 turns is
placed within this field. The area of the loop of wire is 5.0 cm2 and it is placed perpendicularly to the field.
The coil is quickly removed from the magnetic field in 0.10 seconds.
What is the magnitude of the average induced voltage in the loop? (2 marks)
Question 12 (Total 2 marks)
A transformer is considered for use in the following situation. The globe glows brightly as it draws 1.0 ampere.
From this information, calculate the current drawn by the primary coil of the transformer. (2 marks)
Question 13 (Total 2 marks)
An unstable isotope of the element bismuth 83214 undergoes alpha decay. During this process the nucleus
of bismuth changes. Describe the change that the nucleus goes through in terms of the number of protons
and neutrons. (2 marks)
Page 15 of 20
Question 14 (Total 2 marks)
Technetium-99 is commonly used in nuclear medicine for obtaining images of internal organs of the body.
This radioisotope has a half-life of 6 hours. If a sample of 2048 mg of this radioisotope is obtained to be
used, how much technetium-99 would be remaining after 2 days? (2 marks)
Question 15 (Total 5 marks)
The diagram below shows the absorption spectra of an atom which consists of the wavelengths 485 nm (n=2)
and 325 nm (n=3). Assume the electron was initially at the ground state (n=1).
a. Calculate the energy of the level E2 in eV. (2 marks)
b. On the diagram, show the three emission transitions that are possible. (1 mark)
c. Calculate the two highest frequencies which will be seen in the atom’s emission spectrum. (2 marks)
Page 16 of 20
Question 16 (Total 4 marks)
The apparatus in the diagram below is used to investigate the photoelectric effect. Light of wavelength 253
nm ejects photoelectrons from a silver plate. The applied voltage can be varied to prevent photoelectrons
from crossing to the collector electrode.
The work function of the silver surface is 4.70 eV.
a. Determine the maximum kinetic energy (in eV) of the photoelectrons ejected from the silver plate.
(2 marks)
b. Determine the magnitude of the minimum stopping voltage that would be required to prevent the most
energetic photoelectrons from reaching the collector electrode. (1 mark)
c. Calculate the cut-off frequency for the silver surface. (1 mark)
Page 17 of 20
Question 17 (Total 3 marks)
Consider three particles A, B, and C. The masses of these particles are such that:
> >
All three particles have the same momentum. Compare their:
a. Speeds. (1 mark)
b. de Broglie wavelengths. (1 mark)
c. Kinetic energies. (1 mark)
END OF SECTION B
Page 18 of 20
Examination formula and constants
Waves
universal wave equation = =
frequency and period = 1
Snell’s law 11 = 22
Critical angle sin = 21 ,ℎ 2 ≤ 1
Reflection ∠ = ∠
refractive index = ℎ
ℎ ℎ
Speed of light in a vacuum 3.00 × 108 −1 or 300 000 kms−1
Lens formula 1
+ 1
= 1
Magnification = −�
�
Diffraction ∝
ℎ
Young’s slit Δ =
Sound intensity =
, (:−2) ∗ : = 42
Sound Intensity Level (dB) = 10 log �
� ,ℎ = 1.00 × 10−12 Wm−2
String fixed at both ends = 2 = 2
Pipe (Open-open) = 2, , 2
3
, … = , 2 , 3 , …
Pipe (Open-closed) = 4 , 4
3
, 4
5
, … = , 3 , 5 , …
Fields
Electric field between charged
plates =
Field of a point charge =
2
Coulomb’s law = 122 = 8.99 × 109 N m2 C−2
Force on an electric charge =
Energy = = Δ = Δ
Charge of the electron = −1.60 × 10−19 C
Page 19 of 20
Electricity and Magnetism
Current =
Power =
=
= = 2
= 2 ( )
Resistivity =
Ohm’s law ℎ′ → =
=
Combining resistors
() = 1 + 2 + 3 + ⋯
1
() = 11 + 12 + 13 + ⋯
Internal resistance of a battery = −
Magnetic flux Φ = sin
Magnetism = sin (); = sin (); Φ = ; = −ΔΦ
Δ
Faraday + Lenz laws = −ΔΦ
Δ
Alternating current = √2 = √2 = 2
Ideal transformer = = = = →
Modern physics
de Broglie wavelength = ℎ
= ℎ
photon: = ℎ = ℎ
Photoelectric effect = ℎ −
Photon energy = ℎ
Photon momentum = ℎ
De Broglie wavelength = ℎ
Fundamental constants:
Electric charge = −1.60 × 10−19 C
Electron rest mass = 9.11 × 10−31 kg
Proton rest mass = 1.67 × 10−27 kg
Planck’s constant ℎ = 6.63 × 10−34 Js ℎ = 4.14 × 10−15 eVs
Page 20 of 20
MUF0122 Physics Unit 2 Sample
MULTIPLE-CHOICE ANSWER SHEET
Candidates are to fill in the following. Do not write your name or your lecturer’s/teacher’s name on your
examination booklet(s).
Student ID Number:
Desk number:
Campus Location:
Instructions
Indicate your chosen answer by circling the appropriate letter like this:
• Example: A B C D
If you change your mind, clearly cross out your first response and circle your new selection.
• Example: A B C D
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
MCQ TOTAL: /20
(Marker Use Only)
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