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WorksheetsPhotoelectric Effect
Total questions: 22
Worksheet time: 22mins
A particle of light is called a...
Photoelectron
Photon
Proton
Electron
The only way to increase the number of photoelectrons emitted is by increasing the _________ of the light
Intensity
Wavelength
Frequency
Energy
The energy of photoelectrons emitted from a metal surface can be increased by
using light of higher frequency.
using light of longer wavelength.
using light of higher intensity.
using monochromatic, polarized light.
What is the best description of 'threshold frequency'?
The minimum energy needed for electrons to escape a surface.
The maximum kinetic energy that an emitted electron has.
The minimum frequency of a photon that will cause an electron to be emitted.
The frequency that an emitted electron will have.
If the brightness of a beam of light increases without changing its color, the ______ will increase.
number of photons
frequency of the light
energy of the photons
wavelength of the photons
What is the energy, in eV, of a photon that has a wavelength of 620 nm?
1eV
2eV
3eV
4eV
Light of a given wavelength is used to illuminate the surface of a metal. However, no photoelectrons are emitted. This is due to.......
frequency of light is greater than the threshold frequency of a metal
lower intensity of light
wavelength of light is greater than the threshold wavelength
higher intensity of light
The energy of a photon is directly proportional to its _____ and inversely proportional to its ______.
intensity - speed
wavelength - frequency
frequency - wavelength
intensity - wavelength
In the photoelectric effect, if the incident photons have a wavelength that is larger than the threshold wavelength, _______.
electrons will be ejected from the metal surface
there will be photoelectric current
no electrons will be emitted from the metal surface
the kinetic energy of the ejected electrons increases
A metal with a work function of 3.5 eV is exposed to photons with an energy of 3.7 eV. What is the maximum kinetic energy of the emitted photoelectrons?
0.2 eV
0.9 eV
1.1 eV
7.7 eV
What is the energy of a photon with a frequency of 5x1014 Hz?
2.5x10-19 J
3.0x10-19 J
3.3x10-19 J
4.5x10-19 J
When UV light is shone onto the metal cathode, electrons are emitted establishing a photocurrent.
Which of the following changes could cause the photocurrent to stop?
Increasing the potential difference of the power supply.
Increasing the frequency of the UV light.
Increasing the intensity of the UV light.
Changing the metal surface to one with a smaller work function.
To release an electron the energy of the photon had to be more than
zero
the cut off frequency
the work function
the cut off wavelength
The energy of the emitted electron is ------------
hf
h/f
hf + Wo
hf - Wo
The cut off (threshold) frequency is
the highest frequency that releases electrons
always in the red part of the spectrum
always in the purple part of the spectrum
different for different metals
A surface has a work function of 4 x 10⁻¹⁹ J
What is the threshold wavelength?
h = 6.6 x 10⁻³⁴ Js
c = 3 x 10⁸ ms⁻¹
6.0 x 10⁻¹⁴ m
700nm
5 x 10⁻⁷ m
3 x 10⁻⁶ m
Light of a single wavelength is incident on a metal. Electrons are released. The intensity of the light is then increased.
Which of the following changes occur?
Rate of electron emission: increase.
Energy of electrons: increase.
Rate of electron emission: decrease.
Energy of electrons: no change.
Rate of electron emission: decrease.
Energy of electrons: increase.
Rate of electron emission: increase.
Energy of electrons: no change.
The graph shows maximum kinetic energy of emitted electrons against frequency of incident light for a number of different metals.
The work function is determined by:
the x-intercept.
the y-intercept.
the gradient.
the area under the graph.
The graph shows maximum kinetic energy of emitted electrons against frequency of incident light for a number of different metals.
The threshold frequency is determined by:
the x-intercept.
the y-intercept.
the gradient.
the area under the graph.
Which statement about the photoelectric effect is correct?
Electrons are emitted instantaneously.
Electrons are not emitted below a certain wavelength.
You can change the energy of the electrons by changing the intensity.
Electron energy is independent of frequency.
The following observations are made about the photoelectric effect:
1. No electrons are emitted below the threshold frequency.
2. Above the threshold frequency the energy of electrons depends on the frequency of the light.
3. Increasing intensity increases the number of emitted electrons.
4. Energy of electromagnetic radiation is quantised.
Which (if any) of these observations can be explained by a Planck's Quantum theory of light?
All of them.
1, 2 and 4 only.
3 only.
None of them.
What is the maximum kinetic energy of electrons emitted from caesium (Cs), when light of frequency 1x 1015 Hz falls upon the metal? (work function for Cs is 2.0eV)
8.0x10-19 J
4.0 eV
2.0 x10-19 J
2.0 eV
