You have one E-day session to complete this project.
You have one E-day session to complete this project.
Work your way through this project, reading the slides and answering the questions.
REVISION OF EM WAVES
Watch the embedded video below. If you have issues playing it within Formative, you can watch it on You Tube using this link
Question 1
1.
Question 2
2.
Question 3
3.
Question 4
4.
Question 5
5.
Question 6
6.
Copy this worked example into your workbook
Question 7
7.
Please upload a scanned copy of the Worked example table in your workbook, proving you have copied it into your book.
THE PHOTOELECTRIC EFFECT
Question 8
8.
Question 9
9.
Question 10
10.
Question 11
11.
Question 12
12.
Question 13
13.
Question 14
14.
Question 15
15.
Question 16
16.
Question 17
17.
Watch this short video on the photoelectric effect.
You can also watch it on You Tube by clicking this link (first 2:43 min)
Look at what happens when light of various frequencies is shone onto a metal.
Question 18
18.
Question 19
19.
Question 20
20.
Question 21
21.
Other Answer Choices:
threshold frequency
intensity
equal to
energy
less than
frequency
work function
greater than
Question 22
22.
The table below shows the work function (in electron volts) of various metals.
QUESTION: Will the photoelectric effect be observed when light of 710 nm is shone onto the surface of potassium?
ALL OF THESE ANSWERS MUST BE TYPED IN SCIENTIFIC NOTATION
Type the answers for each of these using this as an example: 9,22 x 10-12 should be typed as 9,22 x 10^-12
Step 1: Convert the work function W0 from eV to Joules. Answer: W0 = _______ J.
Step 2: Calculate the threshold frequency f0 of potassium using W0 =hf0. Answer: f0 = _______ Hz.
Step 3: Calculate the frequency of the light using its wavelength. f = _______ Hz.
Step 4: Compare the frequency of the light to the threshold frequency f0. The threshold frequency f0 is _______ (greater than/less than/equal to) the frequency of this light.
Step 5: Therefore, the photoelectric effect _______ (will/will not) be observed.
Question 23
23.
The table below shows the work function (in electron volts) of various metals.
QUESTION: Will the photoelectric effect be observed when light of 710 nm is shone onto the surface of aluminium?
ALL OF THESE ANSWERS MUST BE TYPED IN SCIENTIFIC NOTATION
Type the answers for each of these using this as an example: 9,22 x 10-12 should be typed as 9,22 x 10^-12
Step 1: Convert the work function W0 from eV to Joules. Answer: W0 = _______ J.
Step 2: Calculate the threshold frequency f0 of aluminium using W0 =hf0. Answer: f0 = _______ Hz.
Step 3: Calculate the frequency of the light using its wavelength. f = _______ Hz.
Step 4: Compare the frequency of the light to the threshold frequency f0. The threshold frequency f0 is _______ (greater than/less than/equal to) the frequency of this light.
Step 5: Therefore, the photoelectric effect _______ (will/will not) be observed.
Question 24
24.
Now use the complete photoelectric equation to calculate the maximum velocity of ejected electrons when light of 310 nm is shone onto the surface of sodium, which has a work function of 2,3 eV.
ALL OF THESE ANSWERS MUST BE TYPED IN SCIENTIFIC NOTATION
Type the answers for each of these using this as an example: 9,22 x 10-12 should be typed as 9,22 x 10^-12
E =_______ J
W0 = _______ J
EK = _______ J
∴ 𝓋 = _______ m.s-1
Consider the following photoelectric effect graph obtained for two metals P and Q.
ANSWERS MUST BE TYPED IN SCIENTIFIC NOTATION WHERE APPLICABLE.
Type the answers for each of these using this as an example: 9,22 x 10-12 should be typed as 9,22 x 10^-12
Required
1
Required
1
Required
1
Question 28
28.
Consider the following graph obtained using data from an investigation of the photoelectric effect.
ANSWERS MUST BE TYPED IN SCIENTIFIC NOTATION WHERE APPLICABLE.
Type the answers for each of these using this as an example: 9,22 x 10-12 should be typed as 9,22 x 10^-12
Write the values of :
Work function = _______ eV
Threshold frequency = _______ Hz
Gradient of graph = _______ J.s which represents _______ constant.
The electric and magnetic fields in electromagnetic waves are oriented
parallel to the wave's direction of travel, as well as to each other.
parallel to the waves direction of travel, and perpendicular to each other.
perpendicular to the wave's direction of travel, and parallel to each other.
perpendicular to the wave's direction of travel, and also to each other.
Which measures the number of waves that pass a certain point per second?
Wavelength
Frequency
Speed of light
Amplitude
What happens to wavelength if the frequency of a wave doubles?
halves
doubles
quadruples
Wavelength is unrelated to frequency
Which type of wave has the longest wavelength?
Radio waves
Visible light
X-rays
Gamma rays
What is the relationship between the frequency and energy of a wave?
Inversely proportional
No relationship
Directly proportional
The square of the frequency equals the energy
What defines the colour of light within the visible spectrum?
Amplitude
Polarization
Frequency
Speed
What is the photoelectric effect?
Absorption of electrons when light hits a metal
Reflection of electrons when light shines on a metal
Emission of electrons when light shines on a metal
Emission of protons when light shines on a metal
In the photoelectric effect ....
The energies of electrons liberated by light depend on the frequency of the light
The energies of electrons liberated by light depend on the source of the light
The energies of electrons liberated by light depend on the intensity of the light.
Who proposed the concept of 'quantum' in physics?
Albert Einstein
Isaac Newton
Max Planck
Niels Bohr
What is the term for the smallest discrete amount of any physical quantity?
Quanta
Photon
Quantum
Atom
What is the wavelength and frequency of UV light with energy of 3,74 x 10−18 J?
wavelength (m)
frequency (Hz)
3,62 × 1014
5,67 × 1015
5,29 × 10−8
1,10 × 10−20
The photoelectric effect supports the particle theory of light because:
light photons are always reflected
light's wavelength is always the same
light behaves like a constant wave
light photons are absorbed resulting in electron emission
Which scientist initially explained the photoelectric effect?
Albert Einstein
Niels Bohr
James Clerk Maxwell
Maxwell plank
Which photon is more energetic: A red one or a violet one?
they have the same energy
the red one
the violet one
can't say
What does 'threshold frequency' signify in the context of the photoelectric effect?
Average frequency of light required to eject electrons
Maximum frequency of light to produce photoelectric effect
Lowest frequency of light needed to eject electrons
Constant frequency in photoelectric effect
What does the 'work function' represent in the context of the photoelectric effect?
The constant energy in effect
The minimum energy needed to remove an electron from a particular metal
The maximum energy needed to remove an electron from a particular metal
The average energy needed to add an electron to a particular metal
What happens if the frequency of light is below the threshold frequency?
No electrons are emitted
Electrons are emitted at a slower pace
All electrons are emitted
Only half of the electrons are emitted
According to the photoelectric effect, what determines the kinetic energy of the ejected electrons?
Size of the metal surface
Intensity of the incident light
Color of the incident light
Frequency of the incident light
Which factor does NOT affect the number of electrons emitted in the photoelectric effect?
Metal surface's cleanliness
Frequency of light
Intensity of light
Type of metal used
Increasing the ______________ of the light, increases the energy of the photon.
Increasing the ______________ of the light, increases the number of photons emitted.
If the frequency of light is ______________ the threshold frequency, then no electrons are emitted.
If the frequency of light is _____________ the threshold frequency, then electrons will be emitted with zero kinetic energy.
If the frequency of light is _________________ the threshold frequency, then electrons will be emitted with kinetic energy.
This kinetic energy value is equal to the energy of a photon minus the __________________ of the metal.