<< Chapter < Page Chapter >> Page >

Conceptual questions

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

No

Got questions? Get instant answers now!

In the interpretation of the photoelectric effect, how is it known that an electron does not absorb more than one photon?

Got questions? Get instant answers now!

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?

from the slope

Got questions? Get instant answers now!

Suppose that in the photoelectric-effect experiment we make a plot of the detected current versus the applied potential difference. What information do we obtain from such a plot? Can we determine from it the value of Planck’s constant? Can we determine the work function of the metal?

Got questions? Get instant answers now!

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

Answers may vary

Got questions? Get instant answers now!

Which aspects of the photoelectric effect cannot be explained by classical physics?

Got questions? Get instant answers now!

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.

the particle character

Got questions? Get instant answers now!

The metals sodium, iron, and molybdenum have work functions 2.5 eV, 3.9 eV, and 4.2 eV, respectively. Which of these metals will emit photoelectrons when illuminated with 400 nm light?

Got questions? Get instant answers now!

Problems

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

4.835 × 10 18 Hz; 0.620 Å

Got questions? Get instant answers now!

The wavelengths of visible light range from approximately 400 to 750 nm. What is the corresponding range of photon energies for visible light?

Got questions? Get instant answers now!

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

263 nm; no

Got questions? Get instant answers now!

What is the longest wavelength of radiation that can eject a photoelectron from potassium, given the work function of potassium 2.24 eV? Is it in the visible range?

Got questions? Get instant answers now!

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.

369 eV

Got questions? Get instant answers now!

The work function for potassium is 2.26 eV. What is the cutoff frequency when this metal is used as photoelectrode? What is the stopping potential when for the emitted electrons when this photoelectrode is exposed to radiation of frequency 1200 THz?

Got questions? Get instant answers now!

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 aluminum photoelectrode.

4.09 eV

Got questions? Get instant answers now!

What is the maximum kinetic energy of photoelectrons ejected from sodium by the incident radiation of wavelength 450 nm?

Got questions? Get instant answers now!

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

5.54 eV

Got questions? Get instant answers now!

A 400-nm violet light ejects photoelectrons with a maximum kinetic energy of 0.860 eV from sodium photoelectrode. What is the work function of sodium?

Got questions? Get instant answers now!

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?

a. 1.89 eV; b. 459 THz; c. 1.21 V

Got questions? Get instant answers now!

The cutoff wavelength for the emission of photoelectrons from a particular surface is 500 nm. Find the maximum kinetic energy of the ejected photoelectrons when the surface is illuminated with light of wavelength 600 nm.

Got questions? Get instant answers now!

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?

264 nm; UV

Got questions? Get instant answers now!

Find the wavelength of radiation that can eject 0.10-eV electrons from potassium electrode. The work function for potassium is 2.24 eV. In what range is this radiation?

Got questions? Get instant answers now!

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

1.95 × 10 6 m/s

Got questions? Get instant answers now!

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, University physics volume 3. OpenStax CNX. Nov 04, 2016 Download for free at http://cnx.org/content/col12067/1.4
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'University physics volume 3' conversation and receive update notifications?

Ask