Name: __________________________ Date: _____________



1.
Radio waves travel through space at what speed?
A.
much faster than the speed of light
B.
faster than the speed of light, since their wavelength is longer
C.
slower than the speed of light
D.
at the speed of light, 3 × 108 m/s


2.
White light passes through a prism and separates into a spectrum of colors. All of these colors are recombined into a single beam by means of a lens. What color is this beam?
A.
white
B.
black (there will be no light left)
C.
It will be in the ultraviolet region of the spectrum.
D.
It will be in the infrared region of the spectrum.


3.
White light passes through a prism and separates into a spectrum of colors. A second prism is placed so that only the green light from the first prism falls upon it. After passing through this second prism the light will be
A.
white.
B.
green.
C.
ultraviolet.
D.
infrared.


4.
Light of a single wavelength falls on a screen with two narrow, closely spaced slits. On a second screen, a short distance beyond the first,
A.
nothing will be seen since light cannot pass through narrow slits.
B.
two bright lines corresponding to the two slits will be observed.
C.
a totally random mixture of light and dark will be seen.
D.
a series of bright lines with dark spaces in between will be seen.


5.
Around 1800 William Herschel passed light through a prism and discovered that part of the non-visible radiation in the resulting spectrum would raise the temperature of a thermometer. This portion of the electromagnetic spectrum is
A.
radio.
B.
infrared.
C.
ultraviolet.
D.
X-ray.


6.
An electrical spark, such as lightning, generates electromagnetic radiations over a wide range of wavelengths. How much longer does a pulse of radio energy take to travel between two detector stations 100 m apart than a pulse of ultraviolet radiation from the same spark?
A.
much longer, since radio waves have much longer wavelengths and therefore travel slower
B.
much shorter, since long-wavelength radiations travel faster
C.
just a little longer, since the high-frequency UV radiation travels faster than the low-frequency radio waves
D.
The time is identical, since both pulses travel at the speed of light.


7.
Visible light occupies which position in the whole electromagnetic spectrum?
A.
between radio and infrared radiation
B.
between ultraviolet and X-rays
C.
between infrared and ultraviolet
D.
between infrared and microwave


8.
In order of increasing frequency some of the colors which the visible spectrum contains are
A.
blue, red, yellow
B.
red, blue, yellow
C.
red, yellow, blue
D.
blue, yellow, red


9.
Choose the correct sequence of electromagnetic radiations, in order of increasing wavelengths.
A.
radio, IR, visible, UV
B.
UV, visible, radio, IR
C.
UV, visible, IR, radio
D.
visible, UV, IR, radio


10.
In terms of wavelengths, gamma rays are
A.
the shortest-wavelength electromagnetic waves.
B.
intermediate between radio and infrared waves.
C.
intermediate between X-rays and ultraviolet waves.
D.
the longest-wavelength electromagnetic waves.


11.
Which of the following is an electromagnetic wave?
A.
microwave
B.
gravitational wave
C.
cosmic ray proton
D.
sound wave


12.
What is the one fundamental difference between X-rays and radio waves?
A.
They always come from different sources.
B.
Their wavelengths are very different.
C.
Radio waves are always wavelike, while X-rays always behave like particles.
D.
Their speeds in outer space are different.


13.
Electromagnetic radiation moving through space with the speed of light consists of oscillating
A.
electric and magnetic fields, always inseparable, always having the same frequency and wavelength, and traveling in the same direction.
B.
electric fields, with magnetic fields occasionally accompanying them, moving in the same direction.
C.
electric and magnetic fields moving in opposite directions along the same line in space.
D.
magnetic fields that over time and distance change to oscillating electric fields and back again.


14.
In a radio wave transmitter (such as that used by a radio or TV station), when the frequency of the signals is increased, the
A.
wavelength is decreased.
B.
speed of transmission of the waves is increased.
C.
wavelength and speed of transmission both increase.
D.
wavelength remains constant.


15.
The temperature of a gas cloud in space is directly related to and representative of the
A.
number of atomic collisions per second within the cloud.
B.
average speed of its atoms.
C.
density of the cloud.
D.
color of the cloud.


16.
On the absolute scale of temperature (in kelvins), the zero of the scale corresponds to the
A.
freezing point of hydrogen.
B.
melting point of ice.
C.
mean temperature of space.
D.
temperature at which motions of atoms and molecules essentially cease.


17.
The temperature of boiling water at ordinary pressures on the Kelvin (absolute) scale is
A.
373 K.
B.
273 K.
C.
212 K.
D.
100 K.


18.
An ideal blackbody in physics and astronomy is an object that
A.
absorbs all electromagnetic radiation but emits none.
B.
emits only infrared light and so looks black to the eye.
C.
does not emit or absorb any electromagnetic radiation.
D.
absorbs and emits electromagnetic radiation at all wavelengths.


19.
When a rod of metal is heated intensely, its predominant color
A.
remains predominantly red as the intensity of light increases.
B.
is white, all colors mixed together, as the intensity of light increases.
C.
changes from red, through orange to white, and then to blue.
D.
changes from blue through white, then orange and finally red, when it becomes red-hot at its hottest.


20.
A photon is
A.
a positively charged particle in the atomic nucleus.
B.
an element with a high atomic number.
C.
a particle which orbits the nucleus of an atom.
D.
a bundle of pure energy.


21.
The energy of a photon of X-rays, compared to the energy of a photon of visible light, is
A.
about the same.
B.
much lower.
C.
variable and can be higher or lower under certain circumstances and in certain positions in the universe.
D.
much higher.


22.
Which is the correct sequence of electromagnetic radiation in order of increasing energy of the photons (or quanta)?
A.
visible light, UV radiation, X-rays, gamma rays
B.
radio waves, microwaves, gamma rays, UV radiation
C.
gamma rays, radio waves, X-rays, infrared rays
D.
visible light, microwave, radio waves, infrared rays.


23.
The chemical makeup of a star's surface is obtained by
A.
measuring the chemical elements present in the stellar wind.
B.
theoretical methods, considering the evolution of the star.
C.
taking a sample of the surface with a space probe.
D.
spectroscopy of the light emitted by the star.


24.
Spectral lines are of particular importance in astronomy because
A.
each different element has a characteristic line spectrum.
B.
they can be observed through a diffraction grating.
C.
they are the only light bright enough to be seen at large distances.
D.
only stars produce bright line spectra.


25.
Why is the sky blue?
A.
The air molecules absorb red light better than blue light, allowing more blue light to reach our eyes.
B.
The air molecules scatter blue light better than red light, so more blue light reaches our eyes.
C.
The air molecules scatter red light better than blue light, so less red light reaches our eyes.
D.
The air molecules absorb blue light better than red light, making the sky appear bluer.


26.
The setting Sun appears red because
A.
its light is scattered by a thicker layer of air than during the day.
B.
red light is more refracted around the horizon than is blue light.
C.
the Sun is cooler in the evening.
D.
red light is more diffracted around the horizon than is blue light.


27.
The basic makeup of an atom is
A.
small, negatively charged particles orbiting around a central positive charge.
B.
negative and positive charges mixed uniformly over the volume of the atom.
C.
small, positively charged particles orbiting around a central negative charge.
D.
miniature planets, possibly with miniature people, gravitationally bound in orbits around a miniature star.


28.
The typical size of an atom is
A.
10–6 m.
B.
10–8 m.
C.
1 m.
D.
10–10 m.


29.
The parameter of an atom that defines its unique position in the periodic table is
A.
the total number of protons and neutrons in the nucleus.
B.
its temperature.
C.
the number of protons in the nucleus.
D.
its size.


30.
The specific colors of light emitted by an atom in a hot, thin gas (e.g., in a tube in a laboratory or a gas cloud in space) are caused by
A.
the vibrations of the electrons within the atom.
B.
an electron dropping into the nucleus and causing changes in the energy of the nucleus.
C.
electrons jumping to lower energy levels, losing energy as they do so.
D.
protons jumping from level to level.


31.
An atom that has had one or more electrons removed is known as
A.
an ion.
B.
a molecule.
C.
an excited atom.
D.
an isotope.


32.
An ionized hydrogen atom is simply
A.
a helium nucleus.
B.
a neutron.
C.
an electron.
D.
a proton.


33.
According to the Doppler effect,
A.
the wavelength of light is shifted to a shorter wavelength if the source of light is moving toward you.
B.
the wavelength of light is shifted to a longer wavelength if the source of the light is moving toward you.
C.
the wavelength of peak emission of light from a source changes as the temperature of the source changes.
D.
spectral lines are split into two or more wavelengths when the source of the light is in a strong magnetic field.



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