Q1) Which of the following quantities are "quantized?"
(1) The potential energy at each rung of a ladder.
(2) The potential energy along the length of a slide.
(3) Wavelength of a standing wave on a string.
(4) The settings on an analog radio dial.
(5) The settings on a digital radio dial.
1) 1 and 3
2) 2 and 4
3) 1, 3, and 4
4) 1, 3, and 5
Q2) The quantization of energy, E = nhf, is not important for an
ordinary pendulum because:
1) the formula applies only to mass-spring oscillators
2) the allowed energy levels are too closely spaced
3) the allowed energy levels are too widely spaced
4) the formula applies only to atoms
5) the value of h for a pendulum is too large
Q3) Determine the energy of a single photon in a beam of
light of wavelength 450 nm.
1) 2.0 eV
2) 2.5 eV
3) 2.8 eV
4) 4.2 eV
5) 4.5 eV
Q4) An ultraviolet lamp emits light of wavelength 400 nm,
at the rate (power) of 400 W. An infrared lamp emits light of
wavelength 700 nm, also at the rate of 400 W. Which lamp
emits photons at the greater rate?
1) 400 nm
2) 700 nm
3) they both emit photons at the same rate
Q5) A laser emits a single, 2.0-ms pulse of light that has a
frequency of 2.83 × 1011 Hz and a total power of 75,000 W. How
many photons are in the pulse?
1) 8.0 × 1023
2) 1.6 × 1024
3) 2.4 × 1025
4) 3.2 × 1025
5) 4.0 × 1026
Q6) A xenon arc lamp is covered with an interference filter that only
transmits light of 400-nm wavelength. When the transmitted light
strikes a metal surface, a stream of electrons emerges from the
metal. If the intensity of the light striking the surface is doubled,
1) more electrons are emitted in a given time interval.
2) the electrons that are emitted are more energetic.
3) both of the above.
4) neither of the above.
Q7) A xenon arc lamp is covered with an interference filter that only
transmits light of 400- nm wavelength. When the transmitted light strikes
a metal surface, a stream of electrons emerges from the metal. The
interference filter is then replaced with one transmitting at 300 nm and the
lamp adjusted so that the intensity of the light striking the surface is the
same as it was for the 400-nm light. With the 300-nm light,
1) more electrons are emitted in a given time interval.
2) the electrons which are emitted are more energetic.
3) both are true.
4) both are false.
Q8) Photons of energy 6 eV cause electrons to be emitted from a
certain metal with a maximum kinetic energy of 2 eV. If photons
of twice the wavelength are incident on this metal which one of the
following statements is true?
1) No electrons will be emitted.
2) Electrons will be emitted with a maximum kinetic energy of 1 eV.
3) Electrons will be emitted with a maximum kinetic energy of 8 eV.
4) Electrons will be emitted with a maximum kinetic energy of 10 eV.
5) Electrons will be emitted with a maximum kinetic energy of 20 eV.
Q9) In a photoelectric effect experiment at a frequency above cut
off, the number of electrons ejected is proportional to:
1) their kinetic energy
2) their potential energy
3) the work function
4) the frequency of the incident light
5) the number of photons that hit the sample
Q10) How many of following statements about the photoelectric effect are
true? (a) The greater the frequency of the incident light is, the greater is
the stopping potential. (b) The greater the intensity of the incident light is,
the greater is the cutoff frequency. (c) The greater the work function of the
target material is, the greater is the stopping potential. (d) The greater the
work function of the target material is, the greater is the cutoff frequency.
(e) The greater the frequency of the incident light is, the greater is the
maximum kinetic energy of the ejected electrons. (f) The greater the
energy of the photons is, the smaller is the stopping potential
1) 1
2) 2
3) 3
4) 4
5) 5
Q11) In the photoelectric effect (for a given target and a given
frequency of the incident light), which of these quantities, if any,
depend upon the intensity of the incident light beam: (a) Kmax of
electron, (b) the maximum photoelectric current, (c) the stopping
potential, (d) the cutoff frequency?
1) a
2) a and c
3) b
4) a, b, and c
5) b and d
Q12) The work function for a particular metal is
4.0 eV. Which one of the following best describes the wavelength
of electromagnetic radiation needed to eject electrons from this
metal?
1) 310 nm or greater
2) 310 nm or less
3) 620 nm or greater
4) 620 nm or less
5) 800 nm or greater
Q13) The stopping potential for electrons ejected by 6.8×1014-Hz
electromagnetic radiation incident on a certain sample is 1.8V. The
kinetic energy of the most energetic electrons ejected and the work
function of the sample, respectively, are:
1) 1.8 eV, 2.8 eV
2) 1.8 eV, 1.0 eV
3) 1.8 eV, 4.6 eV
4) 2.8 eV, 1.0 eV
5) 1.0 eV, 4.6 eV
Q14) A tunable laser is directed upon a metal. When the wavelength
of the light just reaches 720 nm, electrons are ejected from the
surface. What is the work function of the metal?
1) 0.58 eV
2) 1.7 eV
3) 520 eV
4) 1960 eV
Q15) Can the collision between an electron and a
photon ever result in the photon gaining energy?
1) yes
2) no
Q16) If the kinetic energy of an electron doubles, the
wavelength of the electron changes by a factor of:
1) 1/sqrt(2)
2) 1/2
3) 1/4
4) sqrt(2)
5) 2
Q17) In the Compton effect, a photon of wavelength λ and frequency f hits
an electron that is initially at rest. Which one of the following occurs as a
result of the collision?
1) The photon is absorbed completely.
2) The photon gains energy, so the final photon has a frequency greater
than f.
3) The photon gains energy, so the final photon has a wavelength greater
than λ.
4) The photon loses energy, so the final photon has a frequency less than f.
5) The photon loses energy, so the final photon has a wavelength less than λ.
Q18) In Compton scattering from stationary particles the
maximum change in wavelength can be made smaller by using:
1) higher frequency radiation
2) lower frequency radiation
3) more massive particles
4) less massive particles
5) particles with greater charge
Q19) In Compton scattering from stationary electrons the
frequency of the emitted light is independent of:
1) the frequency of the incident light
2) the recoil speed of the electron
3) the scattering angle
4) the electron recoil energy
5) none of the above
Q20) Compare Compton scattering for x rays (  20 pm) and
visible light (  500 nm) at a particular angle of scattering.
Which has the greater (a) Compton shift, and (b) energy
imparted to the electron?
1) (a) x-rays (b) x-rays
2) (a) x-rays (b) visible light
3) (a) visible light (b) visible light
4) (a) visible light (b) x-rays
5) none of the above
Q21) In the Compton effect, a photon of wavelength  and frequency f
hits an electron that is initially at rest. Which one of the following
occurs as a result of the collision?
1) The photon is absorbed completely.
2) The photons gains energy, so the final photon has a frequency > f.
3) The photons gains energy, so the final photon has a wavelength > .
4) The photons loses energy, so the final photon has a frequency < f.
5) The photons loses energy, so the final photon has a wavelength < .
Q22) Incident x-rays in a Compton scattering experiment have a
wavelength of 0.400 nm. Determine the wavelength of the scattered
x-rays that are detected at an angle of 80.0o. The Compton
wavelength of the electron is 2.43  10-12 m.
1) 0.041 nm
4) 0.402 nm
2) 0.398 nm
5) 0.403 nm
3) 0.399 nm
Q23) Consider the following:
1) a photoelectric process in which some emitted electrons have kinetic
energy greater than hf, where f is the frequency of the incident light.
2) a photoelectric process in which all emitted electrons have energy less
than hf.
3) Compton scattering from stationary electrons for which the emitted
light has a wavelength that is greater than that of the incident light.
4) Compton scattering from stationary electrons for which the emitted
light has a wavelength that is less than that of the incident light.
The only possible processes are:
1) 1
4) 2 and 3
2) 3
5) 2 and 4
3) 1 and 3
Q24) The uncertainty in position of an electron is
5.0  10-10 m. The uncertainty in its momentum (in kg m/s)
must be:
1) less than 10-26
2) less than 10-22
3) more than 10-25
4) more than 10-23
5) more than 10-21
Q25) The uncertainty in position of an electron in a certain state is
5×10-10 m. The uncertainty in its momentum might be:
1) 5.0 × 10-24 kg·m/s
2) 4.0 × 10-24 kg·m/s
3) 3.0 × 10-24 kg·m/s
4) all of the above
5) none of the above
Q26) If Planck’s constant were changed to 660 J•s, what would be
the minimum uncertainty in the position of a 120-kg football player
running at a speed of 3.5 m/s?
1) 0.032 m
2) 0.065 m
3) 0.13 m
4) 0.25 m
5) 0.50 m
Q27) Is the wavelength of the transmitted (matter) wave
in the figure below larger than, smaller than, or the
same as that of the incident wave?
1) larger than
2) smaller than
3) the same as
Q28) In order to tunnel through a potential barrier a particle must:
1) have energy greater than the barrier height
2) have spin
3) be massive
4) have a wavelength longer than the barrier width
5) none of the above
Q29) An electron with energy E is incident on a potential energy
barrier of height Epot and thickness L. The probability of tunneling
increases if:
1) E decreases without any other changes
2) Epot increases without any other changes
3) L decreases without any other changes
4) E and Epot increase by the same amount
5) E and Epot decrease by the same amount