WorksheetsAP Physics Modern
Total questions: 24
Worksheet time: 6hrs 0mins
As the temperature of a blackbody increases, what happens to the peak wavelength of the light it
radiates?
It gets longer
It gets shorter
he wavelength is not affected by the temperature of the object.
Two identical metal bars are heated up until they are both glowing. One of them is "red hot" and the
other is "blue hot." Which one is hotter, the one that glows red or the one that glows blue?
the red one
the blue one
We cannot tell without knowing more about the two bars.
A photon of blue light and a photon of red light are traveling in vacuum. The photon of blue light
has a smaller wavelength than a photon of red light and travels with the same
has a smaller wavelength than a photon of red light and travels with a greater speed.
has a longer wavelength than a photon of red light and travels with the same speed.
has a longer wavelength than a photon of red light and travels with a greater speed.
Increasing the brightness of a beam of light without changing its color will increase
the number of photons per second traveling in the beam.
he energy of each photon
he speed of the photons.
the frequency of the light.
the wavelength of the photons.
If the wavelength of a photon is doubled, what happens to its energy?
It is reduced to one-half of its original value.
It stays the same.
It is doubled
It is increased to four times its original value.
It is reduced to one-fourth of its original value.
Light of a given wavelength is used to illuminate the surface of a metal, however, no photoelectrons are emitted. In order to cause electrons to be ejected from the surface of this metal you should ....
use light of a longer wavelength.
use light of a shorter wavelength
use light of the same wavelength but increase its intensity
use light of the same wavelength but decrease its intensity.
A blue laser beam is incident on a metallic surface, causing electrons to be ejected from the metal. If
the frequency of the laser beam is increased while the intensity of the beam is held fixed
the rate of ejected electrons will decrease and their maximum kinetic energy will increase
the rate of ejected electrons will remain the same but their maximum kinetic energy will increase.
the rate of ejected electrons will increase and their maximum kinetic energy will increase.
he rate of ejected electrons will remain the same but their maximum kinetic energy will decrease.
Monochromatic light falls on a metal surface and electrons are ejected. If the intensity of the light is increased, what will happen to the ejection rate and maximum energy of the electrons?
greater rate; same maximum energy
same rate; greater maximum energy
greater rate; greater maximum energy.
same rate; same maximum energy.
When the surface of a metal is exposed to blue light, electrons are emitted. If the intensity of the blue light is increased, which of the following things will also increase?
the number of electrons ejected per second
the maximum kinetic energy of the ejected electrons
the time lag between the onset of the absorption of light and the ejection of electrons
the work function
How much energy is carried by a photon of light having frequency 110 GHz? (h=6.626 x 10-34 J • s)
1.1 x 10-20 J
1.4 x 10-22 J
7.3 x 10-23 J
1.3 x 10-25 J
What frequency of electromagnetic radiation has photons of energy 4.7 x 10-25 J? (h= 6.626 x 10-34 J .s)
710 kHz
4.7 MHz
710 MHz
1.4 GHz
Gamma rays are photons with very high energy. What is the wavelength of a gamma-ray photon with energy 7.7 x 10-13 J? (c= 3.0 x 108 m/s, h= 6.626 x 10-34 J·s)
2.6 x 10-13 m
3.9 x 10-13 m
3.1 x 10-13 m
3.5 x 10-13 m
When an electron jumps from an orbit where n= 4 to one where n=2
a photon is emitted.
a photon is absorbed.
two photons are emitted.
two photons are absorbed.
None of the given answers are correct.
The energy difference between adjacent orbit radii in a hydrogen atom
increases with increasing values of n.
decreases with increasing values of n.
remains constant for all values of n.
varies randomly with increasing values of n.
In making a transition from state n=1 to state n= 2, the hydrogen atom must
absorb a photon of energy 10.2 eV.
emit a photon of energy 10.2 eV.
The primary reason that very large nuclei are unstable is due to
the cumulative repulsive force of the protons.
the cumulative attractive force between the protons and the orbiting electrons.
the repulsive force between the neutrons and the protons.
the extreme weakness of the gravitational attraction of the protons.
Atomic nuclei that are all isotopes of an element all have the same
number of nucleons
mass
number of protons
number of neutrons
The atomic number of an atom is equal to the number of what particles in the nucleus?
protons
neutrons
nucleons
positrons
The mass number of an atom is equal to the number of what particles in the nucleus?
protons
neutrons
nucleons
electrons
positrons
The atomic number and mass number for calcium-39 are 20 and 39, respectively. How many
neutrons are in one atom?
1
19
20
39
59
The two strongest forces that act between protons in a nucleus are
the weak nuclear and electromagnetic forces.
the weak nuclear and the gravitational forces
the electrostatic and the gravitational forces.
he strong nuclear and the electrostatic forces.
What happens to the half-life of a radioactive substance as it decays?
It remains constant.
It increases.
It decreases at a constant rate.
It decreases at an exponential rate.
The energy radiated by a star, such as the sun, results chiefly from
beta decay.
alpha decay.
fission reactions.
fusion reactions.
Inside the nucleus, the weakest of the four fundamental forces is
the weak nuclear force.
the electromagnetic force.
the gravitational force.
the strong nuclear force.
