Exam 3 Concepts Flashcards
constructive interference produces…
bigger amplitude
destructive interference produces…
smaller amplitude
m
order of refraction
more slits means
sharper image
N
number of slits
a diffraction produces an interference pattern. If the number of slits is increasing and everything else is the same then…
fringes get brighter and narrower.
spectroscopy
measuring wavelengths of emissions
order of electromagnetic spectrum
radio, micro, infrared, visible, ultraviolet, x rays, gamma rays
two light sources are said to be coherent if they are
-same frequency
-maintain a constant distinct phase
two beams of coherent light start out at the same point in phase and travel different paths to arrive at point P. If the maximum constructive interference is to occur at point P, the two beams must travel paths that differ by
a whole number of wavelengths
monochromatic coherent light shines through a pair of slits if the distance between these slits is decreased what regards the interference pattern
distance between minima increases, distance between maxima increases
in a double slit interference separation is greatest when illuminate the double slit with
red light
in a single slit diffraction, when the slit is reduced what happens to the width of the central bright fringe
becomes wider
if a diffraction grating is heated and expands what happens to the angular location of the first order maximum
moves towards the centerline
when a beam of light is traveling in air is reflected by a glass surface there is..
90 degree phase change in the reflected beam
when a light wave enters into a medium of different refractive index
only its speed and wavelength change
if a sheet containing a single thin slit is heated (without damaging it) and therefore expands, what happens to the width of the central bright diffraction region on a distant screen
it gets wider
radio waves are diffracted by large objects, whereas visible light is not noticeably diffracted. why?
wavelength of light is smaller than the wavelength of radio waves
what increases the separation between the bright fringes in the diffraction pattern formed by a diffraction grating
increase in the wavelength of the light used
light of the same wavelength passes through two diffraction gratings. one grating has 4000 lines/cm and the other one has 6000 lines/cm which grating will spread the light through a larger angle in the first order pattern
the 6000 line grating
light reflects off the surface of lake superior. what phase shift does it undergo
180 degrees
when a beam of light that is traveling in glass strikes an air boundary at the surface of the glass there is
no phase change reflected in the beam
a light beam has a speed c in vacuum and speed v in a certain plastic the index of refraction of this plastic is
n= c/v
light enters air from water (n=1.33) the angle of refraction will be
less than the angle of incidence
light goes from material having refractive index of n1 into a material with refractive index n2. if the refracted light is bent away from normal, what can you conclude about the indices of refraction
n1>n2
what describes the image formed by a plane mirror
virtual and upright
if you stand in front of a convex mirror at the same distance from it as its radius of curvature
you will see your image and you will appear smaller than you
which teerm describes lenses that are thinner at the center than at the edges
diverging and concave lenses
a convex Lense has a focal length f. if an object is located at infinity the image formed is located at a distance from the lens
of f
if an object is placed between a convex lens and its focal point, the image formed is
virtual and upright
starting from very far away an object is moved closer and closer to a diverging lens eventually reaching the lens. what happens to its image formed by the lens
the image eventually chamges from real to virtual
if the magnification of a mirror or lens is negative it means that
the image is inverted
the image formed by a single concave lens
is always virtual
the index of refraction of a type of glass is 1.50 and the index of refraction of water is 1.33. if light enters water from this glass the angle of refraction will be
greater to the angle of incidence
a beam of light traveling in air strikes a glass slab at an angle of incidence less than 90 degrees. after entering the glass slab, what does the beam of light do
bends closer to the normal at the point of contact
the critical angle for a beam of light passing from water into air is 48.8 degrees this means that all light rays with an angle of incidence on the water is greater than 48.8 degrees will be
totally reflected
describe lenses that are thicker at the center than at the edges
converging or convex
a convex lens has focal length f, if an object is placed at a distance of 2f from the lens on the principal axis the image is located at a distance from the lens
infinity
starting from very far away an object is moved closer to a converging lens eventually reaching the lens. what happens to the image formed by the lens
the image eventually changes from virtual to real
describe the image formed by a single diverging lens
always virtual, upright, and smaller than the object
if a single lens forms a virtual image of an object then
the lens could be either diverging or converging lens
a negative magnification for a mirror means that
the image is inverted and the mirror is concave
an object placed Infront of a convex mirror at a distance larger than twice the magnitude of the focal length of the mirror the image will appear
upright and reduced
when you look into the backside of a spoon you seen
a little you rightside up
single concave spherical mirrors produce images that
could be smaller than, larger than, or the same size as the actual object depending on the placement of the object
the primary reason that very large nuclei are unstable is due to
the cumulative repulsive force of the protons
atomic nuclei that are all isotopes of an element all have the same
number of protons
all nuclei of a given element have the same number of
protons
the atomic number and mass for calcium-39 are 20 and 39 respectively, how many neutrons are in one atom
19
the atomic mass unit is defined as
one twelfth the mass of a carbon 12 atom
a stable nucleus contains many protons very close to each other, all positively charged. why do the protons nit fly apart due to mutual coulomb repulsion
an attractive nuclear force in the nucleus counteracts the effect of the coulomb forces
an alpha particle is also known as
a helium nucleus
if the half life of a material is 45 years how much of it will be left after 100 years
less than 1/4 but more than 1/8
what is the meaning of the term critical mass in regard to nuclear fission
minimum amount of fissionable material required to sustain a chain reaction
the main fuel for producing energy in the center of the sun is
hydrogen
the two strongest forces that act between protons in the nucleus are
the strong nuclear and the electrostatic forces
main reason there is a limit to the size of a stable nucleus
the short range nature of the strong nuclear force
a beta - particle is also known as
an electron
the nuclei of 4 2 He is also known as
alpha particles
when a beta + particle is emitted from an unstable nucleus, the atomic number of the nucleus
decreases by one
the chief hazard of radiation damage to living cells is
due to ionization
strong reflection means..
constructive
weak reflection means…
destructive
specular reflection
reflection from a smooth shiny surface
incident ray
ray coming into the reflective surface
diffuse reflection
reflecting incident light in all directions
s is positive when
always
s is negative when
never
s’ is positive when
real image, opposite side of lens or in front of a mirror
s ’ is negative when
virtual image, same side of lens, behind a mirror
f is positive when
converging lens or mirror
f is negative when
diverging lens or mirror
m is positive when
image is upright
m is negative when
image is inverted
total internal reflection
light ray is unable to refract through a boundary and instead reflects back into
