Q: Which equation correctly expresses the photoelectric effect, relating the maximum kinetic energy of ejected electrons to the energy of incident photons and the work function of the material?

$$KE_{\text{max}} = hf - \phi$$

Q: What is the lowest frequency of light that will free electrons from a material with cutoff wavelength $$\lambda_c = 288\ \text{nm}$$?

$$1.04 \times 10$$^{15}$$\ \text{Hz}$$

Q: A surface has a work function $$\phi = 6.35\ \text{eV}. $$What is the cutoff frequency $$f_c$$ for this surface?

$$1.53 \times 10$$^{15}$$\ \text{Hz}$$

Q: A photoelectron achieves a maximum kinetic energy of $$2.50\ \text{eV}. $$What is its maximum speed?

$$9.37 \times 10$$^{5}$$\ \text{m/s}$$

Q: If the maximum kinetic energy of photoelectrons is $$KE_{\text{max}} = 2.50\ \text{eV}$$, what is the corresponding value in joules?

$$4.00 \times 10$$^{-19}$$\ \text{J}$$

Question 1

Which equation correctly expresses the photoelectric effect, relating the maximum kinetic energy of ejected electrons to the energy of incident photons and the work function of the material?

Accepted Answer

$$KE_{	ext{max}} = hf - \phi$$

Question 2

A metal surface has a work function $$\phi = 4.31\ 	ext{eV}. If $$photons with energy $$5.50\ 	ext{eV}$$ strike the surface, what is the maximum kinetic energy of the ejected electrons?

Accepted Answer

$$1.19\ 	ext{eV}$$

Question 3

Given a work function $$\phi = 2.24\ 	ext{eV}$$, what is the cutoff wavelength $$\lambda_c$$ for the photoelectric effect?

Accepted Answer

$$555\ 	ext{nm}$$

Question 4

If the cutoff wavelength for a material is $$\lambda_c = 288\ 	ext{nm}$$, what is the work function $$\phi of $$the material?

Accepted Answer

$$4.31\ 	ext{eV}$$

Question 5

What is the lowest frequency of light that will free electrons from a material with cutoff wavelength $$\lambda_c = 288\ 	ext{nm}$$?

Accepted Answer

$$1.04 	imes 10$$^{15}$$\ 	ext{Hz}$$

Question 6

A surface has a work function $$\phi = 6.35\ 	ext{eV}. $$What is the cutoff frequency $$f_c$$ for this surface?

Accepted Answer

$$1.53 	imes 10$$^{15}$$\ 	ext{Hz}$$

Question 7

What is the cutoff wavelength $$\lambda_c$$ for a surface with cutoff frequency $$f_c = 1.53 	imes 10$$^{15}$$\ 	ext{Hz}$$?

Accepted Answer

$$196\ 	ext{nm}$$

Question 8

If the stopping potential for a photoelectric experiment is $$V_s = 2.15\ 	ext{V}$$, what is the maximum kinetic energy of the ejected electrons?

Accepted Answer

$$2.15\ 	ext{eV}$$

Question 9

A photoelectron achieves a maximum kinetic energy of $$2.50\ 	ext{eV}. $$What is its maximum speed?

Accepted Answer

$$9.37 	imes 10$$^{5}$$\ 	ext{m/s}$$

Question 10

What is the energy of a photon with wavelength $$\lambda = 400\ 	ext{nm}$$?

Accepted Answer

$$3.11\ 	ext{eV}$$

Question 11

If the work function of silver is $$\phi_{	ext{silver}} = 4.73\ 	ext{eV}$$ and the maximum kinetic energy of photoelectrons is $$2.50\ 	ext{eV}$$, what is the wavelength of the incident light?

Accepted Answer

$$172\ 	ext{nm}$$

Question 12

A photon with wavelength $$546.1\ 	ext{nm}$$ ejects an electron with kinetic energy $$0.376\ 	ext{eV}. $$What is the work function $$\phi of $$the material?

Accepted Answer

$$1.90\ 	ext{eV}$$

Question 13

If the maximum kinetic energy of photoelectrons is $$0.216\ 	ext{eV}$$, what is the stopping potential $$\Delta V_s$$?

Accepted Answer

$$0.216\ 	ext{V}$$

Question 14

Which of the following best describes the relationship between the maximum kinetic energy of photoelectrons and the frequency of incident light, as shown in the provided graphs?

Accepted Answer

The maximum kinetic energy increases linearly with frequency above the cutoff frequency.

Question 15

If the work function of a material is $$\phi = 1.90\ 	ext{eV}$$ and the wavelength of incident light is $$587.5\ 	ext{nm}$$, what is the maximum kinetic energy of the ejected electrons?

Accepted Answer

$$0.216\ 	ext{eV}$$

Question 16

Which physical quantity is directly measured by the stopping potential in a photoelectric experiment?

Accepted Answer

The maximum kinetic energy of the ejected electrons

Question 17

If the maximum kinetic energy of photoelectrons is $$KE_{	ext{max}} = 2.50\ 	ext{eV}$$, what is the corresponding value in joules?

Accepted Answer

$$4.00 	imes 10$$^{-19}$$\ 	ext{J}$$

Question 18

Which of the following best explains why electrons are not ejected from a material when the frequency of incident light is below the cutoff frequency?

Accepted Answer

The energy of the photons is less than the work function of the material.

Photoelectric Effect: Cutoff Wavelength, Frequency, Work Function, and Kinetic Energy

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