6.2 Photoelectric Effect

Threshold frequency, work function, and stopping potential in electron ejection, and why intensity-independent kinetic energy defeats a wave account.

University Physics Volume 3, 6.2 Photoelectric Effect

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14 exercises

6.2 Exercise 1

A yellow 589-nm light is incident on a surface whose work function is 1.20 eV. What is the stopping potential? What is the cut-off wavelength?

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6.2 Exercise 2

Cut-off frequency for the photoelectric effect in some materials is $8.0 \times 10^{13} \text{Hz} .$ When the incident light has a frequency of $1.2 \times 10^{14} \text{Hz} ,$ the stopping potential is measured as – 0.16 V. Estimate a value of Planck’s constant from these data (in units $\text{J} \cdot \text{s}$ and $\text{eV} \cdot \text{s}$ ) and determine the percentage error of your estimation.

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6.2 Exercise 3

For the same monochromatic light source, would the photoelectric effect occur for all metals?

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6.2 Exercise 5

Explain how you can determine the work function from a plot of the stopping potential versus the frequency of the incident radiation in a photoelectric effect experiment. Can you determine the value of Planck’s constant from this plot?

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6.2 Exercise 7

Speculate how increasing the temperature of a photoelectrode affects the outcomes of the photoelectric effect experiment.

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6.2 Exercise 9

Is the photoelectric effect a consequence of the wave character of radiation or is it a consequence of the particle character of radiation? Explain briefly.

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6.2 Exercise 11

A photon has energy 20 keV. What are its frequency and wavelength?

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6.2 Exercise 13

What is the longest wavelength of radiation that can eject a photoelectron from silver? Is it in the visible range?

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6.2 Exercise 15

Estimate the binding energy of electrons in magnesium, given that the wavelength of 337 nm is the longest wavelength that a photon may have to eject a photoelectron from magnesium photoelectrode.

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6.2 Exercise 17

Estimate the work function of aluminum, given that the wavelength of 304 nm is the longest wavelength that a photon may have to eject a photoelectron from an aluminum photoelectrode.

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6.2 Exercise 19

A 120-nm UV radiation illuminates a silver-plated electrode. What is the maximum kinetic energy of the ejected photoelectrons?

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6.2 Exercise 21

A 600-nm light falls on a photoelectric surface and electrons with the maximum kinetic energy of 0.17 eV are emitted. Determine (a) the work function and (b) the cutoff frequency of the surface. (c) What is the stopping potential when the surface is illuminated with light of wavelength 400 nm?

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6.2 Exercise 23

Find the wavelength of radiation that can eject 2.00-eV electrons from calcium electrode. The work function for calcium is 2.71 eV. In what range is this radiation?

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6.2 Exercise 25

Find the maximum velocity of photoelectrons ejected by an 80-nm radiation, if the work function of photoelectrode is 4.73 eV.

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