Open Stax Exam 2
What is the name for a wave that is a combination of two waves?
complex wave
What type of element is used to gather light in large astronomical telescopes?
concave mirror
How is the production of a rainbow affected by dispersion?
a Sunlight is dispersed only as it enters and as it exits a raindrop.
A scientist directs a beam of electrons onto a crystal and collects the scattered electrons. What will be observed by the scientist?
a diffraction pattern
What type of corrective lenses would an eye doctor most likely prescribe for a patient with astigmatism?
a prescription with a cylindrical correction
An object is positioned in front of a lens with its base resting on the principal axis. Describe two rays that could be traced from the top of the object and through the lens that would locate the top of an image.
a ray parallel to the axis and a ray through the center of the lens
What aspect of light does geometric optics deal with?
light traveling as a ray
Fluorescent dyes in clothing can absorb ultraviolet light and then convert it to visible light. Is it possible to make a dye that absorbs visible light and then emits ultraviolet?
no
Why is electric power transmitted at high voltage?
to reduce energy loss during transmission
Is the following statement true or false? Refraction is useful in fiber optic cables for transmitting signals. a
true
If you shine a narrow beam of white light into a prism, which color of light will be refracted the most?
violet
What type of image is produced by the eyepiece lens of a microscope?
virtual and inverted
Consider these colors of light: violet, red, green. Part A: Put these light waves in order according to wavelength, from shortest wavelength to longest wavelength. Part B: Put these light waves in order according to frequency, from lowest frequency to highest frequency.
wavelength: violet, green, red frequency: red, green, violet
Which values of 𝑚m denote the location of destructive interference in a single-slit diffraction pattern?
whole integers, excluding zero
True or False: Interference patterns more closely follow the particle model of light.
False
True or False: Photon momentum more directly supports the wave model of light.
False
True or False: wave-particle duality can be observed in objects on the macroscopic scale.
False
What happens when a wave propagates to the end of a string that is loosely attached?
It reflects without inversion.
What is the width of a single slit through which 520 nm520 nm green light passes to form a first diffraction minimum at an angle of 20.0∘?
1.52𝜇m
Which of these applications of atomic excitation do not depend on metastable states? fluorescence phosphorescence lasers holograms
1 and 4
What did Rutherford's scattering experiment reveal about the structure of atoms? 1Most of the space inside the atom is empty. 2Most of the mass of the atom is concentrated in the center. 3The center of the atom has a small, dense nucleus. 4The nucleus of the atom contains many smaller particles.
1, 2, and 3
Which of the following properties of an electron in an atom can be expressed with quantum numbers? energy linear momentum angular momentum spin
1, 3, and 4
An electron in an atom has angular momentum projection quantum number ml=2ml=2. What is the smallest possible value for its angular momentum quantum number ll?
2
Atoms with approximately what number of nucleons have the greatest binding energy per nucleon?
60
Which aspect of the photoelectric effect cannot be explained without photons?
A threshold frequency is required for electrons to be ejected.
Part A. Can you see a virtual image? Part B. Can you photograph one? Explain your answers.
A. Yes. B. Yes. An image from a flat mirror can be photographed.
The isotope iodine-131 has a half-life of 8.1 days. A scientist places a 100gram sample of iodine-131 into a sealed container that has a mass of 50grams. After 8.1 days, what will the mass of the container and its contents be?
About 150grams
What is the average energy needed to remove a nucleon from a nucleus?
About 8MeV
232Th undergoes radioactive decay and forms 228Ra. What type of decay did it undergo?
Alpha decay
A scientist needs to use a high-𝑍 element in an experiment. What type of element does the term "high-𝑍" imply?
An element with a large number of protons
What is the relationship between temperature and the most intense frequency emitted from a blackbody?
As temperature increases, the most intense frequency emitted also increases.
247Am undergoes radioactive decay and forms 247Cm. What type of decay did it undergo?
Beta decay
Describe the cause of chromatic aberration.
Chromatic aberration results from the dependence of the wavelength of light on the refractive index, which causes dispersion of different colors of light by a lens so that each color has a different focal point.
Explain why an object in water always appears to be at a depth that is more shallow than it actually is.
Because of the refraction of light, the light coming from the object bends away from the normal at the interface of water and air. This causes the object to appear at a location that is above the actual position of the object. Hence, the image appears to be at a depth that is more shallow than the actual depth.
How does the difference between the ranges of the strong nuclear force and the Coulomb force affect the makeup of each atom's nucleus?
Because the range of the Coulomb force is longer, heavier atoms have more neutrons than protons.
One of the decay products of 238U is 226Ra. A rock originally contained 238U, which has a half-life of 4.5×10^9 yr, and 226Ra, which has a half-life of 1,600 yr. After 5×10^9 yr, which isotopes would you expect to be present in significant amounts in the rock?
Both 238U and 226Ra
How is it possible for a bound nucleus to have less mass than its constituent parts?
Bound nucleons have less energy than separated, and therefore less mass. Next
Which colors of the rainbow bend most when refracted?
Colors with a shorter wavelength and higher frequency bend most when refracted.
Under what condition will current flow in a semi-conductive surface?
Current will flow if the energy per photon incident on the surface exceeds the work function of the surface.
What is Huygens's principle?
Each point on a wavefront acts like a tiny wave, and each spreads out at the same speed.
What is electromagnetism?
Electromagnetism is the study of electric and magnetic phenomena.
The equation that gives the points of constructive interference produced by a diffraction grating is 𝑑sin𝜃=𝑚𝜆dsinθ=mλ. Why does that equation look familiar?
It is the same as the equation for constructive interference for a double-slit diffraction pattern.
If you shine a red light from air into water, what happens to the color of the light?
It will remain unchanged because color depends on frequency.
60Co undergoes radioactive decay. The nuclide after the decay is still 60Co. What type of decay did it undergo?
Gamma decay
Which physicist first identified the electron as an independent part of the atom?
J. J. Thomson
Why does increasing the intensity of EM radiation not result in ejected electrons of greater kinetic energy?
Increasing the intensity of EM radiation increases the number of photons striking the surface but does not change the velocity of electrons emitted from the surface. Next
How can light travel from a source to another location?
It can travel through empty space or through a medium.
An accelerator laboratory is considering using a solid-state detector as part of a high-energy experiment. What would be an advantage of using a solid-state detector?
It converts part of the particles' energy directly into electric current.
What happens when a wave crest hits the fixed end of a string?
It inverts and returns as a trough.
An object is placed in front of a concave mirror at a distance that is greater than the focal length of the mirror. Will the image produced by the mirror be real or virtual? Will it be erect or inverted?
It is real and inverted.
How can you calculate the critical angle when light travels from one material into another?
It is the inverse sine of the ratio of the second index of refraction to the first index of refraction.
What colors of light does an object absorb and reflect if it appears red when a white light shines on it?
It reflects red light and absorbs all other colors of light. NextSave
What is the speed of light?
Light travels about 3×10^8m/s3×10^8m/s in a vacuum but slower through matter.
What hypothesis about the structure of matter did de Broglie first make?
Matter has wave-like properties.
Describe how modeling is useful in studying the structure of the atom.
Modeling replaces the real system by something similar but easier to examine.
A lens has a magnification that is negative. What is the orientation of the image?
Negative magnification means the image is inverted and real.
Can a single microwave photon cause cell damage?
No, there is not enough energy associated with a single microwave photon to result in cell damage.
39K and 41K are the two most abundant isotopes of potassium. Should you expect their chemical behaviors to be similar or different?
Similar, because they have the same number of protons
A beam with 𝛼 particles, 𝛽 particles, and 𝛾 rays is directed toward a 3-centimeter thick lead block. Which part of the beam is transmitted through the block?
Some of the 𝛾 rays are transmitted. None of the 𝛼 particles or the 𝛽 particles are transmitted.
Which parameters of a wave are affected during refraction?
Speed and wavelength
Why do lenses but not mirrors have chromatic aberration?
The index of refraction depends on wavelength, but the the law of reflection does not.
Using knowledge of photon energy, why is the inside of a campfire flame yellow while the outside of the flame is red?
The inner campfire flame has more energy and higher frequency. Next
How are the angle of reflection and the angle of incidence of light related?
The angle of reflection minus the angle of incidence equals 0∘0∘.
Suppose you shine monochromatic light through a single slit. How would the angle at which the mimima are produced change if the slit width were decreased?
The angle would increase.
What does the splitting of atomic spectral lines imply about the direction of the angular momentum of an electron in an atom?
The direction of the angular momentum is quantized.
Suppose during a Young's double slit experiment, you observe light and dark fringes on a screen. What would be the effect if the wavelength of light were increased?
The distance between light fringes would increase.
Compare the distance of an object from a mirror to the apparent distance of its virtual image behind the mirror.
The distances of the image and the object from the mirror are the same.
How does a medium's index of refraction affect wavelength?
The higher the index of refraction, the shorter the wavelength in the medium.
Use the law of reflection to explain why you cannot see your image reflected in a pond when it is raining.
The image formed by a rough surface is blurred.
If a lens has a magnification of -12-12, how does the image compare with the object in height and orientation?
The image is inverted and is half as tall as the object.
An object is placed at a distance from a convex lens that is greater than the focal length of the lens. Describe the image that is formed in terms of its orientation, and whether it is real or virtual.
The image is inverted and real.
An object is placed between the focal point and a convex lens. Describe the image that is formed in terms of its orientation, and whether the image is real or virtual.
The image is virtual and erect.
Does light change direction toward or away from the normal when it goes from diamond to water? Explain.
The light bends away from the normal because the index of refraction of diamond is greater than that of water.
Light travels from glass to air; the index of refraction for glass is 1.5. If the incident angle is 60°, what is the refracted angle?
The light reflects back into the glass
A red laser and green laser both emit light of the same intensity. Compare the number of photons emitted by each laser and the energy supplied by each photon.
The number of photons emitted by the red laser is greater, but the energy supplied by each green photon is greater.
If you want a telescope to have the greatest angular magnification possible, what should be the relationship of the focal lengths of the objective and the eyepiece?
The objective should have a long focal length, and the eyepiece should have a short focal length.
What is the advantage of using a diffraction grating rather than a double slit for dispersing light into a spectrum?
The pattern has a higher resolution.
How would the interference pattern be observed for a beam of electrons if you attempted to track the exact path of a single electron?
The pattern would disappear.
Identify the process that allows light and images to travel through a tube that is not straight.
The process is total internal reflection of light.
Explain why using a parabolic mirror for a car headlight throws much more light on the highway than a flat mirror.
The rays become parallel after reflection.
A person timing the sunset looks at his watch and then at the setting Sun. Describe what happened inside his eyes that allowed him to see his watch clearly one second and then see the setting Sun clearly.
The shape of the lens was changed by muscles, and thus its focal length was also changed, so that each of the images focused on the retina.
What limitations would you encounter if you attempted to simultaneously measure the energy and the lifetime of a pion?
The uncertainty in its energy multiplied by the uncertainty in time is always greater than or equal to h/4π.
True or false: If EM radiation were simply a wave, low frequency light would be capable of ejecting electrons from a surface.
True
What limitations would you encounter if you attempted to simultaneously measure the position and the momentum of a proton?
The uncertainty in its momentum multiplied by the uncertainty in its position is always greater than or equal to h/4π.
Which aspect of a beam of monochromatic light changes when it passes from a vacuum into glass, and how does it change?
The wavelength decreases.
Which aspect of a beam of monochromatic light changes when it passes from a vacuum into water, and how does it change?
The wavelength decreases.
Which aspect of monochromatic green light changes when it passes from a vacuum into diamond, and how does it change?
The wavelength decreases.
The temperature of a blackbody radiator is increased. What will happen to the most intense wavelength of light emitted as this increase occurs?
The wavelength of the most intense radiation will decrease.
Why is it reasonable to treat light as a ray instead of a wave in everyday situations?
The wavelengths of light waves are so short that the wave effects are negligible.
Why does monochromatic light that travels through a single slit produce smaller maxima on either side of the central maximum?
The wavelets from the slit arrive in different phases. Next
Under what circumstances is an image located at the focal point of a concave mirror? Explain.
This happens when incident rays are parallel to the principal axis.
Go outside in the sunlight and observe your shadow. It has fuzzy edges, even if you do not. Is this a diffraction effect? Explain.
This is a diffraction effect. Every point on the edge of your shadow acts as the origin for a new wavefront.
Is the following statement true or false? The light wave from a bulb is an example of a periodic wave.
True
How are wavelength, frequency, and energy related on the electromagnetic spectrum?
Waves with the lowest energy have the longest wavelengths and lowest frequencies.
What type of image is produced by a coma aberration?
an image that has a pear shape
What color would a red apple appear to be if you shine a blue light on it?
black
How do waves superimpose on one another?
by adding their disturbances
Which type of corrective lens does a farsighted person need?
converging lens
Which phenomenon best shows the wave nature of electrons?
crystal diffraction
Which two types of variables are included in Snell's law?
dThe two types of variables are refractive index of a material and the angle made by a light ray with the normal.
X-rays carry more energy than visible light. Compare the frequencies and wavelengths of these two types of EM radiation.
dVisible light has lower frequencies and longer wavelengths than X-rays.
Identify a behavior of light that indicates wave characteristics but not particle characteristics.
diffraction
How does the object distance, 𝑑odo, compare with the focal length, 𝑓f, for a concave mirror that produces an image that is real and inverted?
do>fdo>f, where 𝑑odo and 𝑓f are object distance and focal length, respectively.
What does "emf" stand for?
electromotive force
Where must you stand near a concave mirror in order for the mirror not to produce your image?
exactly at the focal point
What color would a white sheet of paper appear to be if you shine a green light on the paper?
green
Where does the image form in the eye of a nearsighted person?
in front of the retina
What aspect of the blackbody spectrum forced Planck to propose energy quantization?
its shape
Where is the object placed in a compound microscope?
just beyond the focal point of the objective lens
Which type of tomography uses the simultaneous detection of two photons emitted in opposite directions?
positron emission tomography
Wolfgang Pauli hypothesized an exclusion principle. This principle says two electrons in an atom cannot have the same what?
quantum state
What type of image is formed by the objective lens of a microscope?
real and inverted
A patient injected with a radiopharmaceutical is examined with an Anger camera. What type of imaging technique was used to examine the patient?
single-photon-emission computed tomography
What is the optimal distance between the eyepiece and the objective of a telescope?
slightly less than the sum of their focal lengths
Give an example of a situation in which superposition is useful.
superposition of waves for signal modulation and transmission
This statement is related to resolution: "Two point sources are just resolved when _______."
the center of the diffraction pattern of one point source is directly over the first minimum of the diffraction pattern of the other
Which part of the eye controls the amount of light that enters?
the iris
What is the mathematical relationship linking the energy of a photon to its frequency?
𝐸=𝑛ℎ𝑓
A beam with 𝛼α particles, 𝛽 particles, and 𝛾γ rays at a given energy is directed toward a 1-centimeter thick block of lithium. Which is most likely to interact with a lithium atom?
𝛼 particles, because they travel slower than the others Next
A principle related to resolution states, "Two point sources are just resolved when the center of the diffraction pattern of one is directly over the first minimum of the diffraction pattern of the other." Write the equation that expresses that principle.
𝜃=1.22𝜆/𝐷
