Frage 1
Frage
A point source is to be used with a concave mirror to produce a beam of parallel light.The source should be placed:
Antworten
-
As close to the mirror as possible
-
At the center of curvature
-
Midway between the center of curvature and the focal point
-
Midway between the center of curvature and the mirror
-
Midway between the focal point and the mirror
Frage 2
Frage
Light from a small region of an ordinary incandescent bulb is passed through a yellow filter and then serves as the source for a Young’s double-slit experiment. Which of the following changes would cause the interference pattern to be more closely spaced?
Antworten
-
Use slits that are closer together
-
Use a light source of lower intensity
-
Use a light source of higher intensity
-
Use a blue filter instead of a yellow filter
-
Move the light source further away from the slits
Frage 3
Frage
In an experiment to measure the wavelength of light using a double slit, it is found that the fringes are too close together to easily count them.To spread out the fringe pattern,one could:
Antworten
-
Decrease the slit separation
-
Increase the slit separation
-
Increase the width of each slit
-
Decrease the width of each slit
-
None of these
Frage 4
Frage
If two light waves are coherent:
Antworten
-
Their amplitudes are the same
-
Their frequencies are the same
-
Their wavelengths are the same
-
Their phase difference is constant
-
The difference in their frequencies is constant
Frage 5
Frage
The magnitude of the momentum of a particle can never exceed:
Antworten
-
mc, where m is its mass
-
E/c, where E is its total energy
-
K/c, where K is its kinetic energy
-
None of the above, but there is an upper limit
-
None of the above; there is no upper limit
Frage 6
Frage
The units of the Planck constant h are those of:
Antworten
-
Energy
-
Power
-
Momentum
-
Angular momentum
-
Frequency
Frage 7
Frage
The quantization of energy, E = nhf, is not important for an ordinary pendulum because:
Antworten
-
The formula applies only to mass-spring oscillators
-
The allowed energy levels are too closely spaced
-
The allowed energy levels are too widely spaced
-
The formula applies only to atoms
-
The value of h for a pendulum is too large
Frage 8
Frage
The wavelength of light beam B is twice the wavelength of light beam B. The energy of a photon in beam A is:
Antworten
-
Half the energy of a photon in beam B
-
One-fourth the energy of a photon in beam B
-
Equal to the energy of a photon in beam B
-
Twice the energy of a photon in beam B
-
Four times the energy of a photon in beam B
Frage 9
Frage
Which of the following electromagnetic radiations has photons with the greatest energy?
Antworten
-
Blue light
-
Yellow light
-
X rays
-
Radio waves
-
Microwaves
Frage 10
Frage
Which of the following electromagnetic radiations has photons with the greatest momentum:
Antworten
-
Blue light
-
X rays
-
Radio waves
-
Yellow light
Frage 11
Frage
In a photoelectric effect experiment no electrons are ejected if the frequency of the incident light is less than A/h, where h is the Planck constant and A is:
Antworten
-
The maximum energy needed to eject the least energetic electron
-
The minimum energy needed to eject the least energetic electron
-
The maximum energy needed to eject the most energetic electron
-
The minimum energy needed to eject the most energetic electron
-
The intensity of the incident light
Frage 12
Frage
The probability that a particle is in a given small region of space is proportional to:
Antworten
-
Its energy
-
Its momentum
-
The frequency of its wave function
-
The wavelength of its wave function
-
The square of the magnitude of its wave function
Frage 13
Frage
Maxwell’s equations are to electric and magnetic fields as equation is to the wave function for a particle:
Antworten
-
Einstein’s
-
Fermi’s
-
Newton’s
-
Schr.odinger’s
-
Bohr’s
Frage 14
Frage
The energy of a particle in a one-dimensional trap with zero potential energy in the interior and infinite potential energy at the walls is proportional to (n = quantum number:
Frage 15
Frage
A particle is trapped in a one-dimensional well with infinite potential energy at the walls Three possible pairs of energy levels are
1) n = 3 and n = 1
2) n = 3 and n = 2
3) n = 4 and n = 3
Order these pairs according to the difference in energy, least to greatest
Antworten
-
1, 2, 3
-
3, 2, 1
-
2, 3, 1
-
1, 3, 2
-
3, 1, 2
Frage 16
Frage
The ground state energy of an electron in a one-dimensional trap with zero potential energy in the interior and infinite potential energy at the walls:
Antworten
-
Is zero
-
Decreases with temperature
-
Increases with temperature
-
Is independent of temperature
-
Oscillates with time
Frage 17
Frage
The ionization energy of an atom in its ground state is:
Antworten
-
The energy required to remove the least energetic electron
-
The energy required to remove the most energetic electron
-
The energy difference between the most energetic electron and the least energetic electron
-
The same as the energy of a Kα-photon
-
The same as the excitation energy of the most energetic electron
Frage 18
Antworten
-
Excited atoms are stimulated to emit photons by radiation external to the laser
-
The transitions for laser emission are directly to the ground state
-
The states which give rise to laser emission are usually very unstable states that decay rapidly
-
The state in which an atom is initially excited is never between two states that are involved in a stimulated emission
-
A minimum of two energy levels are required
Frage 19
Frage
The relation between the disintegration constant λ and the half-life T of a radioactive substance is:
Antworten
-
λ = 2T
-
λ = 1/T
-
λ = 2/T
-
λT = ln2
-
λT = ln(1/2)
Frage 20
Frage
In a nuclear reactor the fissionable fuel is formed into pellets rather than finely ground and the pellets are mixed with the moderator This reduces the probability of
Antworten
-
Non-fissioning absorption of neutrons
-
Loss of neutrons through the reactor container
-
Absorption of two neutrons by single fissionable nucleus
-
Loss of neutrons in the control rods
-
None of the above
Frage 21
Frage
In a subcritical nuclear reactor:
Antworten
-
The number of fission events per unit time decreases with time
-
The number of fission events per unit time increases with time
-
Each fission event produces fewer neutrons than when the reactor is critical
-
Each fission event produces more neutrons than when the reactor is critical
-
None of the above
Frage 22
Frage
In the normal operation of a nuclear reactor:
Antworten
-
Control rods are adjusted so the reactor is subcritical
-
Control rods are adjusted so the reactor is critical
-
The moderating fluid is drained
-
The moderating fluid is continually recycled
-
None of the above
Frage 23
Frage
Max Plank found his constant h
Antworten
-
To get same result as Rayleigh and Jeans
-
To describe experimental intensity distribution of blackbody at ultraviolet region
-
To describe Compton scattering
-
To describe experimental intensity distribution of blackbody at long wavelengths
-
To describe experimental intensity distribution of blackbody at all wavelengths
Frage 24
Frage
Energy and momentum of photon is respectively:
Antworten
-
ħω; 1/λ
-
ħω; 2πħ/λ
-
m0c^2; 2π/λ
-
m0c^2; 2πħ/λ
-
ħω; m0c^2
Frage 25
Frage
Nucleus of which element has no neutron:
Frage 26
Frage
The number of electron states in a shell with principal quantum number n = 3 is:
Frage 27
Frage
The activity of radioactive substance is
Frage 28
Frage
A hydrogen atom is in its ground state. Incident on the atom is a photon having an energy of 10.5 eV. What is the result?
Frage 29
Frage
A hydrogen atom makes a transition from the n = 3 level to n = 2 level. It then makes a transition from the n = 2 level to the n = 1 level. Which transition results in emission of the longest-wavelength photon?
Frage 30
Frage
A section of hollow pipe and a solid cylinder
have the same radius, mass, and length. They
both rotate about their long central axes with
the same angular speed. Which object has
the higher rotational kinetic energy?
Frage 31
Frage
Two spheres roll down an incline, starting
from rest. Sphere A has the same mass and
radius as sphere B, but sphere A is solid
while sphere B is hollow. Which arrives at
the bottom first?
Antworten
-
Sphere A
-
Sphere B
-
Both arrive
-
At the same time
-
Impossible to determine
Frage 32
Frage
Two solid spheres roll down an incline,
starting from rest. Sphere A has twice the
mass and twice the radius of sphere B.
Which arrives at the bottom first?
Frage 33
Frage
Which of the following statements is not true regarding a mass- spring system that moves with simple harmonic motion in absence of friction?
Antworten
-
The total energy of the system remains constant
-
The energy of the system is continually transformed between kinetic and potential energy
-
The total energy of the system is proportional to the square of the amplitude
-
The potential energy stored in the system is greatest when the mass passes through the equilibrium position.
Frage 34
Frage
For an object undergoing simple harmonic motion,
Antworten
-
The amplitudes are usually regarded as being large
-
The acceleration is greatest when the displacement is greatest
-
The acceleration is greatest when the speed is greatest
-
The maximum potential energy is larger than the maximum kinetic energy
-
The displacement is greatest when the speed is greatest
Frage 35
Frage
A skater can spin faster by pulling in her arms closer to her body or spin slower by spreading her arms out from her body. This is due to
Frage 36
Frage
The moment of inertia of a body depends on
Frage 37
Frage
The moment of inertia of a wheel about its axle does not depend upon its:
Antworten
-
Diameter
-
Mass
-
Distribution of mass
-
Speed of rotation
Frage 38
Frage
A mechanical wave generally does NOT
Frage 39
Frage
A woman sits on a spinning stool with her arms folded. When she extends her arms, which of the following occurs
Antworten
-
She increases her moment of inertia, thus increasing her angular speed
-
She increases her moment of inertia, thus decreasing her angular speed.
-
She decreases her moment of inertia, thus increasing her angular speed
-
She decreases her moment of inertia, thus decreasing her angular speed
-
Her angular speed remains constant by conservation of angular momentum
Frage 40
Frage
In elastic collision between the two bodies __________.
Antworten
-
Only momentum of the system is conserved
-
Only the kinetic Energy of the system is conserved
-
Both the kinetic Energy and Momentum of the system remain the same
-
Total energy is not conserved