Quantum physics

The photoelectric effect provided experimental evidence that light

• has a wave characteristic

• is a transverse wave

• can diffract

• can constructtively and destructively interfere

• has a particle characteristic

In a photoelectric experiment, the frequency of light is steadily increased. Which statement below is NOT correct?

• Below the threshold frequency, no electrons are emitted

• Above the threshold frequency, electrons are emitted

• Increasing the frequency of light increases the energy of the emitted electrons

• Increasing the frequency of light increases the potential difference of the photocell

• Increasing the frequency of light increases the induced current

In a photoelecric experiment, the intensity of light is steadily increased. Which statement below is correct?

• Below the certain intensity, no electrons are emitted

• Above the certain intensity, electrons are emitted

• Increasing the intensity of light increases the induced current

• Increasing the intensity of light increases the potential difference of the photocell

• Increasing the intensity of light increases the energy of the emitted electrons

The graph below depicts the maximum kinetic energy of emitted electrons as a function of frequency for a photoelectric process. What does the slope of the graphed function represent?

• Speed of light, c

• Electron volt, eV

• Planck's constant, h

• Electric potential, V

• Wavelength, λ

Determine the work function Φ, for this metal.

• $1.6\cdot10^{-19}J$

• $1.105\cdot10^{15}J$

• $3.99\cdot10^{-19}J$
  

• $5.06\cdot10^{-19}J$

What is the kinetic energy of a photoelectron if the energy of the incident photon is 7.5 eV?

• 10 eV

• 5 eV

• 2.5 eV

• 7.5 eV

Which metal has the highest threshold frequency?

• potassium

• sodium

• zinc

• tungsten

• platinum

Which metal has the lowest work function?

• potassium

• sodium

• zinc

• tungsten

• platinum

When a clean metal in a vacuum is irradiated with ultraviolet radiation, electrons are emitted. What would be the effect if the intensity of the ultraviolet radiation is increased?

• Stopping potential – the same, photocurrent – increase

• Stopping potential – the same, photocurrent – the same

• Stopping potential – increase, photocurrent – increase

• Stopping potential – the same, photocurrent – the same

In a photoelectric emission experiment, photoelectrons are produced when an electromagnetic radiation is incident on a metal surface. Both the intensity and the wavelength of the electromagnetic radiation are then reduced resulting in

• A reduction in the maximum kinetic energy of the electrons but an increase in there are of emission.

• A reduction in both the maximum kinetic energy of the electrons and their rate of emission.

• An increase in both the maximum kinetic energy of the photoelectrons and their rate of emission.

• An increase in the maximum kinetic energy of the photoelectrons but a reduction in their rate of emission.