1 The electromagnetic waves named below with the shortest wavelength are
2 Telescopes with low magnification must have
more light gathering power
less image distortion
x ratio of objective to eyepiece focal lengths near one
3 If a telescope lens were increased to four times its diameter, the image would have
twice its previous intensity
twice its previous size
four times its previous focal length
x 16 times its previous brightness
4 The Sun's peak emission is yellow-white. Which of the below are hotter than the Sun?
an orange star
x a blue star
a red star
both orange and red star
all three stars
5 The first to accurately measure the speed of light was
x Olaus Romer
James Clerk Maxwell
6 The speed of light in a vacuum is known to
change with the speed of the source
depend on its frequency
x be fixed in value
vary with the motion of the observer
depend on its wavelength
7 For a given medium, light frequency depends inversely on its
8 The atmosphere of the Earth strongly absorbs
visible and radio waves
infrared and microwaves
radio and gamma rays
x ultraviolet and x-rays
9 Absorption spectra are usually associated with
x cold gases
electrons losing energy
10 The frequency at which a star's light intensity is maximum increases with the star's
x surface temperature
11 The temperature of the surface of the Earth is near
x 300 Kelvin
3 million Kelvin
12 If a star's surface had a temperature twice our Sun's, compared to the Sun, its light intensity would be
x sixteen times
thirty two times
13 Both light and sound waves
are vibrations of a material
have the same speed
x can diffract around barriers
carry the same energy per particle
are transverse waves
14 The following is an ionizing radiation
x gamma rays
15 The light emitted from excited hydrogen has definite colors because
these are the colors of the electrons
the electron in hydrogen behaves like a planet
x the hydrogen electron energies are quantized
light energy is quantized
colors correspond to frequencies
16 If you view the spectrum of a cold gas in space nearby to a star, you are likely to see
emission lines without a continuous spectrum
absorption lines in a weak continuous spectrum
a continuous spectrum without emission lines
x emission lines and a weak continuous spectrum
absorption lines in a strong continuous spectrum
17 The resolution of optical telescopes on the ground are principally limited by
x atmospheric absorption and turbulence
optical instrument aberrations
18 When the Viking spacecraft is four times its current distance from Earth, the radio signal we detect will be
four times weaker
x sixteen times weaker
two hundred and fifty six times weaker
one thousand and twenty four times weaker
four thousand times weaker
19 From the spectrum of a star, we can measure
x the star's surface temperature
the star's mass
the star's radius
the star's power
the star's brightness
20 Chromatic aberration is caused by
x light dispersion in lenses
color deflection from a mirror
distortion due to the shape of a lens
a deviation of a mirror's focus
absorption in the lens
21 Spherical aberration can occur with
x lenses and mirrors
22 Hertz experimentally verified the existence of
x radio waves
23 Newton discovered
light is a wave
x prismatic colors
light is a collection of particles
the speed of light is constant
24 Light can be polarized because it is
x a transverse wave
a longitudinal wave
a collection of particles
able to be magnetized
produced at the poles
25 The energy of a photon increases with
x light frequency
26 Light is known to show
only wave properties
simultaneously both particle and wave particles
only particle properties
neither wave nor particle properties
x particle or wave properties, but not both at once
27 Light is generated and detected by
charges at rest
x accelerating charges
charges moving at fixed speed
28 The law of reflection can explain
x the action of mirrors
lens image formation
the dispersion of light
the resolution of a telescope
the diffraction of waves
29 The absorption spectrum of hydrogen
x is present in starlight
is made by heating hydrogen gas
is the same as helium
was predicted by Einstein
30 The resolution of the human eye is about
one degree of arc
x one minute of arc
one second of arc
as good as a 1 meter telescope
half a centimeter
31 The inner electrons in heavy elements absorb light with frequencies in the
32 Maxwell's Theory of Electromagnetism
x predicted the speed of light
was known to Newton
has been found to be incomplete
was developed in 1965
contains Newton's laws
33 Destructive interference is a signature of
x all forms of waves
impedance in materials
34 The change in color of a hot body as it is heated is predicted by
x Wien's law
35 The diffractive limit of a telescope is due to
x the wave properties of light
the energy carried by photons
36 When light passes through a prism of glass,
The prism absorbs colors from different parts of the broad beam coming-out of the prism, leaving the complementary colors that we see.
The different colors are caused by multiple reflections in the prism and interference between the resulting beams.
The prism adds colors to different parts of the broadly scattered beam coming out of it.
x The different colors or wavelengths of light are separated in angle by the prism.
37 Violet light differs from red light in that
Violet light has a longer wavelength than red light.
Violet light travels more slowly (through a vacuum) than red light.
x Violet light has a shorter wavelength than red light.
Violet light travels more quickly (through a vacuum) than red light.
38 On the absolute scale of temperature (in kelvins), the zero of the scale corresponds to
x The temperature at which motions of atoms and molecules essentially cease
The melting point of ice
The mean temperature of space.
The freezing point of hydrogen
39 An example of an object that emits no radiation at all is
x Any object at a temperature of 0 K
Any object made of ice
Any object with the temperature of outer space
40 Pieces of metal are heated by varying amounts in a flame. The hottest of these will be the one that shows which color most prominently?
41 Where and by what technique was the element helium first discovered?
In the upper atmosphere of Earth, by studying the aurora, or northern lights
In radioactive rocks from uranium deposits
In the laboratory, by heating chemicals in a flame
x On the Sun, from spectroscopy during a solar eclipse
42 The chemical makeup of a star's surface is usually inferred
By theoretical methods, considering evolution of the star
By measuring the chemical elements present in the solar wind
By taking a sample of that surface with a space probe
x By spectroscopy of the light emitted by the star
43 What happens in general when ultraviolet radiation passes through a tube of cool hydrogen gas?
x All of the radiation passes through the tube except for specific wavelengths, which are absorbed by the atoms.
All of the radiation will be absorbed completely.
Some of the radiation at all wavelengths is absorbed, reducing the intensity at all wavelengths uniformly.
All of the radiation passes through the tube unhindered because the hydrogen gases cool and cannot absorb energy.
44 Changes in the observed wavelength of light due to the Doppler effect occurs
Only when the temperature of an object changes
Whenever the light source is moving with respect to the observer (regardless of direction)
Only when the light source has a proper motion (across the line of sight)
x Only when the light source has a radial velocity (toward or away from the observer)
45 Which characteristic property of a glass lens is the most important in bending light rays to form a focused image?
The color of the glass
x The curvature and shape of its surfaces
The diameter or size of the lens
The thickness of the center of the lens
46 When light in air or a vacuum enters the plane surface of a dense transparent medium at an angle to the perpendicular to this surface, which way does the light ray bend?
It does not bend at all, because the material is transparent.
x It bends toward the perpendicular.
It bends so that whatever the incoming angle, the light always travels along the perpendicular to the surface.
It bends away from the perpendicular.
47 Who was the first astronomer to build and use a telescope to observe the moons of Jupiter?
48 The main reason for building larger optical telescopes on the Earth's surface is
To improve the resolution of astronomical objeces
To better magnify images of astronomical objects
x To collect more light from faint objects
For national prestige, with no good scientific reason
49 Colors are perceived differently by our eyes because of their different:
50 Space travelers looking out from the front of their accelerating spacecraft would note that the light emitted from the star system toward which they were moving seemed to be:
x Getting bluer.
Staying the same.
51 Which of the following types of visible light has the highest energy?
52 What is emitted from an atom when one of its electrons makes a transition from a higher energy state to a lower energy state?