Exam 3 Flashcards
The best definition of refraction is
Changing direction when crossing a boundary
A beam of light in air is incident at an angle of 35 degrees to the surface of a rectangular block of clear plastic. The light beam first passes through the block and reemerges from the opposite side into air at what angle to the normal to that surface?
35 degrees
A light ray in air enters and passes through a block of glass. What can be stated with regard to its speed after it emerges from the block?
Speed is the same as that before it entered glass
Which of the following describes what will happen ot a light ray incident on an air-to-glass boundary?
Partial transmission and partial reflection
Which of the following describes what will happen to a light ray incident on an air-to-glass boundary at an angle of incidence less than the critical angle?
Partial reflection and partial transmission
Which of the following describes what will happen to a light ray incident on a glass-to-air boundary at an angle of incidence greater than the critical angle?
Total reflection
A ray of white light, incident upon a glass prism, is dispersed into its various color components. Which one of the following colors experiences the greatest amount of refraction?
Violet
When light from air hits a smooth piece of glass with the ray perpendicular to the glass surface, which of the following will occur?
Reflection and transmission at an angle of 0 degrees
If total internal reflection occurs at a glass-air surface, then
No light is refracted
When light from air hits a smooth piece of glass with the ray perpendicular to the glass surface, the part of the light passing into the glass
Will not change its direction
The person suffering from the problem of myopia
Has difficulty seeing objects placed nearby and will therefore form a smaller image behind the retina
To correct the problem of myopia, you use
a converging lens
If an image was formed in front of the retina rather than behind, the person would suffer from
Hyperopia
To correct for hyperopia, we must use a
Diverging lens
Dispersion occurs when
A material slows down some colors more than others
Which of the following best describes the image for a thin converging lens that forms whenever the object is at a distance less than one focal length from the lens?
Upright, enlarged, and virtual
Which of the following best describes the image for a thin diverging lens that forms whenever the magnitued of the object distance is less than that of the lens’ focal length?
Upright, reduced and virtual
Before light can undergo total internal reflection when incident on material 2 from material 1, what must be true of the indices of refraction?
N1>n2
When light passes from a material with a high index of refraction into material with a low index of refraction
Some light is reflected without a change of phase
The normal eye has a near point of 25 cm. If a given individual’s near point is 73 cm for what problem with the eye doctor prescribe correction?
Hyperopia
A fringe shift occurs for every ___ wavelength movement of the adjustable mirror in a Michelson interferometer
Quarter
According to special theory of relativity, if a 30 year old astronaut sent on a space mission is accelerated to speeds close to that of light and returns to earth after 20 years as measured on earth, what would be his biological age upon returning?
Less than 50 years
As the speed of an object increases, its relativistic momentum
Increases less than its classical momentum
The mass of a proton at rest is m. If the proton is moving so fast that its total energy is 3 times its rest energy, then what is the kinetic energy of the proton.
2mc^2
If the nonzeero momentum of a particle with mass is doubled, what happens to its total energy?
It increases but less than doubling.
An inertial frame of reference is one that
Moves at a constant velocity
Helium neon laser light has a wavelength in air of 632.8 nm. What is the energy of a single photon in the beam?
3.14 E-19
Einstein’s special theory of relativity is based in part on which of the following postulates?
The speed of light is constant
An astronaut moves at a constant velocity of .5c relative to an earth observer. Both astronaut and earth observer measure the interval between heartbeats of the astronaut. Who measures proper time?
The astronaut
Three flat layers of transparent material are stacked upon one another. The top layer has index of refraction n1, the middle has n2 and the bottom one is n3. If n1
There is such an angle but it is not given
At what speed would a clock have to be moving in order to run at a rate that is one-half the rate of a clock at rest?
.866 c
Monochromatic light hits a piece of glass. What happens to the wavelength in the glass as the index of refraction increases?
Decreases
The lowest possible value for the index of refraction is
1
According to the photon energy formula, tripling the frequency of the radiation from a monochromatic source will change the energy content of the individually radiated photons by what factor?
3.0
If a person is farsighted the corrective lens will
Take an object at 25 cm and form an image at the near point
A magnifier uses a
Converging lens to form a virtual image
Even relatively small astronomical telescopes are ordinarily not used for terrestrial observation because
Their images are inverted
A lens with focal length of 10 cm has what power
10.0 diopters
Doubling the focal length of the objective lens of a compound microscope with change the magnification by what factor
1/2
Of the values listed below, which is the greatest possible value for the index of refraction?
2.4
A spaceship is flying past an earth observer as the earth observer measures its length. How is this measured length different for a larger velocity of the spaceship.
It is smaller
A boxcar moves to the right. One light flash moves back to front another moves front to back. A passenger records how long it takes each flash to pass from one end of the boxcar to the other. Which took longer?
They both took the same time
In einsteins thought experiement of lightning striking the front and rear of a train carrying one observer past a second stationary observer, who measures the proper time between the lightning strikes?
Neither
What is the maximum possible arc that can be subtended by a rainbow?
360 degrees
In a one dimmensional system like our train example, two events separated by 1 m are observed to be simultaneous by the stationary observer. To an observer moving at nonzero velocity, these events are observed to be
Not simultaneous
As the angle of incidence is increased for a ray incident on a reflecting surface, the angle between the incident and reflected rays ultimately approaches what value?
180 degrees
The short lifetime of muons created in the upper atmosphere of the earth would not allow them to reach the surface of the earth until their lifetime increased by time dilation. From the reference system of the muons, the muons can reach the surface of the Earth because
Length contraction decreases the distance to the surface of the Earth
