IB Quantum

page 1


1. A photon emitted from the nucleus of an atom contains energy. The ratio of the photon energy to the frequency is
  • A. the speed of light
  • B. the speed of light squared
  • C. Planck's constant
  • D. the photon wavelength

2. Photons can exhibit wave and particle properties. In which of these experiments are these properties evident?

  Wave properties Particle properties
A Double slit interference Diffraction
B Double slit interference The photoelectric effect
C Diffraction Double slit interference
D The photoelectric effect Diffraction
3. In the photoelectric effect, light is incident on a clean metal plate and electrons are lost from the surface of the metal. The amount of energy required to liberate a single electron is equal to
  • A. the photon energy
  • B. the kinetic energy of the electron
  • C. the work function of the metal
  • D. the stopping potential applied

4. Which of the following graphs correctly shows the variation of kinetic energy of the emitted electrons with frequency of applied radiation?

5. A clean sodium metal is tested under a lamp, but no photoelectrons are emitted. To produce photoelectrons, what changes should take place?
  • A. The metal should be replaced with a metal of higher work function
  • B. The lamp should be replaced with an identical one of higher power output
  • C. A higher frequency light source should be used
  • D. A longer wavelength light source should be used

6. The electrons liberated from a clean metal surface produced by the photoelectric effect can be measured by a current flowing in an external circuit. What effect will there be on the current flowing and the stopping potential if the metal is replaced with one with a lower work function?

  photoelectric current stopping potential
A increases increases
B stays the same increases
C increases stays the same
D stays the same decreases


7. The position and the momentum of a particle can never be both known precisely. This law is called

  • A. Schrodinger's hypothesis
  • B. the De Broglie hypothesis
  • C. Heisenberg's uncertainty principle
  • D. Einstein's mass - energy equivalence


8. A beam of electrons is directed at a thin slit as shown in the diagram.



The minimum uncertainty in the momentum of an electron, Δp is

in the x direction
4 π x
in the y direction
4 π x
C. 0 in the x direction
D. 0 in the y direction


9. For an electron in a circular orbit around a hydrogen nucleus (as given by the Bohr model of the atom), the angular momentum is given by

  • A. mv2
  • B. mrv2
  • C. mv2/r
  • D. mrv2


10. The wavefunction of a particle is a function that gives the properties across space. The square of the amplitude of the wavefunction at a point is proportional to the

  • A. intensity of the particle at that point
  • B. probability of the particle being found at that point
  • C. energy of the particle at that point
  • D. uncertainty of the momentum of the particle at that point