Physics ch 27 review
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the main difference between a radio and a sound wave is its
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basic nature
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solar eclipses are seen less commonly than lunar eclipses because
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Earth's shadow on the moon is larger than the moons shadow on Earth
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electromagnetic waves are
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transverse waves
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if an electron vibrates up and down 1000 times each second, it generates an electromagnetic wave having a
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frequency of 1000 Hz
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the main difference between a radio wave and a light wave is its
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wavelength
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electromagnetic waves with higher frequencies have wavelengths that are
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shorter
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the source of all electromagnetic waves is
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vibrating charges
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light that reflects at glancing angles from nonmetallic surfaces, such as glass, water, or roads is
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polarized parallel to the surface
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what is the frequency of an electromagnetic wave having a wavelength of 300,000 km?
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more than 1 Hz
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if 2 polarizing filters are held with their polarization axes at right angles to each other, the amount of light transmitted compared to when their axes are parallel is
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zero
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which of these electromagnetic waves has the shortest wavelength?
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x-rays
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which of the following are fundamentally different from the others?
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sound waves
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compared to its speed in air, the speed of light in water is
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slower
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an ideal polarizing filter will transmit 50% of nonpolarized light incident on it. how much light is transmitted by 2 ideal polarizing filters that are oriented with their axed parallel to each other?
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50%
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which is the ultimate source of electromagnetic waves?
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vibrating charged particles
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compared to the velocity of radio waves, the velocity of visible light waves is
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the same
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which of the following is NOT an electromagnetic wave?
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sound
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what is the wavelength of an electromagnetic wave that has a frequency of 1 Hz?
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more than 1 m
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glass is transparent to visible light, but not to
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infrared and ultraviolet
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if the sun were to disappear right now, we wouldn't know about it for 8 minutes because it takes 8 minutes
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for light to travel from the sun to Earth
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after randomly polarized light passes through a polarizer, it is
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totally polarized
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compared to the wavelength of ultraviolet waves, the wavelength of infrared waves is
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longer
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how far is a light-second?
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300,000 km
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when Roemer took measurements of one of Jupiter's moons (Io) moving behind jupiter, he found his predicted time was off. compared to when Earth was closest to Io, the predicted times when Earth was farthest away form Io were
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late
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electromagnetic waves
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can travel through a vacuum
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the primary purpose of polarized sunglasses is
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to block glare from reflections
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light does not pass through what kind of materials?
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opaque
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the shadow produced by an object held close to a piece of paper in sunlight will be
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sharp
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heat lamps give off mostly
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infrared waves
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clouds
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transmit UV light
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because of absorption, a polarizing filter actually transmit 40% of incident nonpolarized light. 2 polarizing filters with their axes aligned will transmit
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between 40% and 100%
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the shiny surfaces of metals have most to do with
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the free electrons in metal atoms
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light waves are
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transverse waves
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light reflected from a lake surface is polarized
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horizontally
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infrared waves are responsible for sunburns.
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false; ultraviolet
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glass transmits ultraviolet and visible light waves but not infrared waves.
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false
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electromagnetic heat waves are called ultraviolet waves.
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false; infrared
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materials that allow light to pass through them in straight lines are called opaque materials.
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false; transparent
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a thin beam of light is called an x-ray.
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false; ray
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the distance light travels in one year is called a light-year.
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true
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according to Einstein, light consists of massless bundles of electromagnetic energy called photons.
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true
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polarization occurs when waves vibrate in a single direction.
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true
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a total shadow is called an umbra.
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true
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light sometimes acts as a wave and sometimes as a particle.
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true
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energy emitted by vibrating electric charges is carried by electromagnetic waves.
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true
