What angle of incidence is required for total internal reflection?
a 90° angle
a 180° angle
a small angle
a large angle
A small angle.
Which is a curved piece of glass or other transparent material used to refract light?
a concave lens
an optical fiber
a mirror
a reflector
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a concave lens.
How can signals be sent through optical fibers?
by sending pulses of light
by changing the frequency
by changing the amplitude
by changing the color of light
By sending pulses of light.
What instruments use lenses or mirrors to collect and focus light from distant objects?
lasers
optical fibers
telescopes
microscopes
Telescopes.
Where did the term “laser” come from?
the company that created the first laser: “Lazarus Energy Research”
an early science fiction story
the acronym for “light amplification by stimulated emissions of radiation”
the phrase “light as a strong energy resource”
The acronym for “light amplification by stimulated emissions of radiation”.
Which describes the type of light that a laser produces?
incoherent
many different colors
coherent
many different wavelengths
Coherent.
What happens when a material’s index of refraction is higher or lower?
The higher the absolute value of the index of refraction, the more the medium bends the light.
The higher the index of refraction, the more the medium bends the light.
The higher the index of refraction, the less the medium bends the light.
The lower the index of refraction, the more the medium bends the light.
The higher the index of refraction, the more the medium bends the light.
What happens to parallel rays of light as they pass through a concave lens?
They intersect inside of the glass of the lens.
They pass through the lens and intersect at the focal point.
They continue on without intersecting with each other.
They pass through the lens and intersect at the image point.
They continue on without intersecting with each other.
What does a concave lens look like?
the same thickness in the middle and at the edges
thicker in the center than at the edges
thinner in the center than at the edges
flat on one side and bulges out on the other side
Thinner in the center than at the edges.
How many phone conversations can one optical fiber carry at one time?
thousands
millions
one
hundreds
Millions.
How are different wavelengths of light affected by entering a prism?
the longest wavelengths are refracted the most
the longest wavelengths are refracted the least
the longest wavelengths are reflected the least
the shortest wavelengths are refracted the least
The shortest wavelengths are refracted the least.
What is coherent light?
light waves that are out of step, or have crests aligned with crests
light waves that are in step, or have crests aligned with crests
light waves that are out of step, or have crests aligned with troughs
light waves that are in step, or have crests aligned with troughs
Light waves that are in step, or have crests aligned with crests.
In a microscope, where is the specimen placed?
close to the eyepiece
close to the objective
close to the concave mirror
close to the convex mirror
Close to the objective.
How are laser beams that are used as signals usually sent from transmitter to receiver?
through optical fibers
through the air
through optical wires
through a vacuum
Through the air.
What is needed to build a laser?
a partially reflective mirror and a fully reflective mirror
two fully reflective mirrors
a concave lens and a convex lens that are fully reflective
two partially reflective mirrors
Two partially reflective mirrors.
Which device uses lenses to focus light rays and magnify an image of a small, nearby object?
refracting telescope
reflecting telescope
microscope
camera
Microscope.
What is a three-dimensional photograph created by using a laser?
a photogram
a sonogram
a hologram
a thermogram
A hologram.
Why do prisms project a spectrum when a white light shines through them?
the white light causes the absorption of different colors of light from the air
different colors of light are reflected at different angles
different colors of light are refracted at different angles
the white light stimulates the release of colored light from inside the prism
Different colors of light are refracted at different angles.
How does a refracting telescope change the image seen by a scientist?
It uses two convex lenses to make faraway images more visible.
It uses two convex lenses to make small images look larger.
It uses two mirrors and a convex lens to make small images look larger.
It uses two mirrors and a convex lens to make faraway images more visible.
It uses two convex lenses to make faraway images more visible.
What is the bending of light rays as they enter a new medium?
refraction
diffraction
diffuse reflection
regular reflection
Refraction.
A material’s index of refraction is a measure of how much a ray of light _____ when it enters that material at an angle.
reflects
bends
changes color
changes speed
Bends.
In a microscope, what does the objective do?
forms a virtual, enlarged image of the specimen
gathers light from a distant object to form a real image
forms a real, enlarged image of the specimen
gathers light from a distant object to form a virtual image