Question 1

What is the one fundamental difference between X-rays and radio waves?

Accepted Answer

A)  X-rays and radio waves always come from different sources. 
B)  The wavelengths of X-rays and radio waves are very different. 
C)  The speeds of X-rays and radio waves in outer space are different. 
D)  Radio waves are always wavelike, whereas X-rays always behave like particles. 
A)  X-rays and radio waves always come from different sources. 
B)  The wavelengths of X-rays and radio waves are very different. 
C)  The speeds of X-rays and radio waves in outer space are different. 
D)  Radio waves are always wavelike, whereas X-rays always behave like particles.

Question 2

The BEST shape for the cross-section of a simple astronomical mirror to have in order to produce the sharpest images of very distant objects at its prime focus is:

Accepted Answer

A)  parabolic. 
B)  elliptical. 
C)  perfectly flat and smooth. 
D)  spherical. 
A)  parabolic. 
B)  elliptical. 
C)  perfectly flat and smooth. 
D)  spherical.

Question 3

According to modern atomic theory,light emitted by atoms originates from:

Accepted Answer

A)  photons emitted directly from the nucleus. 
B)  transitions of electrons between electron levels of the same atom. 
C)  collisions between atoms. 
D)  electrons emitted from the nucleus. 
A)  photons emitted directly from the nucleus. 
B)  transitions of electrons between electron levels of the same atom. 
C)  collisions between atoms. 
D)  electrons emitted from the nucleus.

Question 4

If we were to send a laser light pulse toward the Moon and some of this light were to be reflected toward Earth from retro-reflectors left on the Moon by astronauts,how long after the transmission of the initial flash would the reflected light be detected through a telescope on Earth?

Accepted Answer

A)  2.56 microseconds 
B)  2.56 seconds 
C)  1.28 seconds 
D)  1.28 milliseconds 
A)  2.56 microseconds 
B)  2.56 seconds 
C)  1.28 seconds 
D)  1.28 milliseconds

Question 5

How does the angular resolution of the 305-m Arecibo radio telescope in Puerto Rico compare with the angular resolution of the 10-m Keck optical telescope on Mauna Kea,Hawaii?

Accepted Answer

A)  It is not possible to compare their angular resolution because they work in different wavelength ranges. 
B)  The 305-m Arecibo telescope has much better angular resolution than the 10-m Keck telescope. 
C)  They have about the same angular resolution because angular resolution is limited by turbulence in Earth's atmosphere, not by mirror diameter. 
D)  The 305-m Arecibo telescope has much worse angular resolution than the 10-m Keck telescope. 
A)  It is not possible to compare their angular resolution because they work in different wavelength ranges. 
B)  The 305-m Arecibo telescope has much better angular resolution than the 10-m Keck telescope. 
C)  They have about the same angular resolution because angular resolution is limited by turbulence in Earth's atmosphere, not by mirror diameter. 
D)  The 305-m Arecibo telescope has much worse angular resolution than the 10-m Keck telescope.

Question 6

In the revolution that overtook physics around 1900,the assumption that Planck made in order to solve the problem concerning the spectrum of radiation emitted by a hot blackbody was that radiation was:

Accepted Answer

A)  emitted as continuous waves whose wavelength was inversely proportional to the temperature of the object. 
B)  emitted in small, discrete packets or quanta of energy whose individual energies were inversely proportional to the wavelength of the light. 
C)  emitted in small, discrete packets or quanta of energy, each quantum having an energy directly proportional to the wavelength of the light. 
D)  made up of small, discrete packets or quanta of energy whose individual energies were all the same, independent of wavelength. 
A)  emitted as continuous waves whose wavelength was inversely proportional to the temperature of the object. 
B)  emitted in small, discrete packets or quanta of energy whose individual energies were inversely proportional to the wavelength of the light. 
C)  emitted in small, discrete packets or quanta of energy, each quantum having an energy directly proportional to the wavelength of the light. 
D)  made up of small, discrete packets or quanta of energy whose individual energies were all the same, independent of wavelength.

Question 7

A refracting telescope has an objective lens of focal length 40 cm and a diameter of 10 cm,and an eyepiece of focal length 5 cm and diameter 1 cm.What is the magnifying power of this telescope?

Accepted Answer

A)  10 times 
B)  40 times 
C)  2 times 
D)  8 times 
A)  10 times 
B)  40 times 
C)  2 times 
D)  8 times

Question 8

Which type of telescope uses a lens as the MAIN optical element?

Accepted Answer

A)  a radio telescope 
B)  a Newtonian telescope 
C)  a Cassegrain telescope 
D)  a refracting telescope 
A)  a radio telescope 
B)  a Newtonian telescope 
C)  a Cassegrain telescope 
D)  a refracting telescope

Question 9

The star P Cygni (in the constellation Cygnus,the Swan)is surrounded by an extensive low-density atmosphere.It has a bright,continuous spectrum with many narrow,dark absorption lines and a few bright emission lines.The bright emission lines are produced by:

Accepted Answer

A)  the low-density atmosphere of the star emitting light in all directions. 
B)  only the part of the low-density atmosphere that is between Earth and the surface of the star. 
C)  all parts of the star, the stellar surface, and the atmosphere, equally. 
D)  the hot, dense, opaque gas at or near the star's surface. 
A)  the low-density atmosphere of the star emitting light in all directions. 
B)  only the part of the low-density atmosphere that is between Earth and the surface of the star. 
C)  all parts of the star, the stellar surface, and the atmosphere, equally. 
D)  the hot, dense, opaque gas at or near the star's surface.

Question 10

A sample of hydrogen gas is heated and produces a spectrum of bright lines.A blackbody spectrum is observed through a cooler sample of hydrogen gas.This situation also produces a line spectrum,and the locations of these lines:

Accepted Answer

A)  are in exactly the same places occupied by the lines in the first bright line spectrum. In fact, these two bright line spectra are identical in every way. 
B)  are in exactly the same places occupied by the lines in the bright line spectra. These lines, however, are dark absorption lines. 
C)  are in different places from the lines in the bright line spectrum. 
D)  match the lines in the bright line spectrum. However, there are many additional lines in this dark line spectrum. 
A)  are in exactly the same places occupied by the lines in the first bright line spectrum. In fact, these two bright line spectra are identical in every way. 
B)  are in exactly the same places occupied by the lines in the bright line spectra. These lines, however, are dark absorption lines. 
C)  are in different places from the lines in the bright line spectrum. 
D)  match the lines in the bright line spectrum. However, there are many additional lines in this dark line spectrum.

Question 11

Two physicists,one on the east coast and one on the west coast of North America,discover that they have constructed ideal blackbodies in their laboratories.The two blackbodies are made from very different materials.Without conducting tests,they know that the radiation emitted by these two objects will be:

Accepted Answer

A)  identical if the blackbodies are at the same temperature but not otherwise. 
B)  identical if the blackbodies have the same size, even if their temperatures are different. 
C)  different because the blackbodies were made from different materials. 
D)  different because the amount of light falling on the blackbodies is likely to be different in the two laboratories. 
A)  identical if the blackbodies are at the same temperature but not otherwise. 
B)  identical if the blackbodies have the same size, even if their temperatures are different. 
C)  different because the blackbodies were made from different materials. 
D)  different because the amount of light falling on the blackbodies is likely to be different in the two laboratories.

Question 12

Which of the following combinations of components of a telescope will produce the WORST angular resolution?

Accepted Answer

A)  a smaller-diameter lens or mirror or radio dish and longer-wavelength electromagnetic radiation 
B)  a larger-diameter lens or mirror or radio dish and shorter-wavelength electromagnetic radiation 
C)  a larger-diameter lens or mirror or radio dish and longer-wavelength electromagnetic radiation 
D)  a smaller-diameter lens or mirror and shorter-wavelength electromagnetic radiation 
A)  a smaller-diameter lens or mirror or radio dish and longer-wavelength electromagnetic radiation 
B)  a larger-diameter lens or mirror or radio dish and shorter-wavelength electromagnetic radiation 
C)  a larger-diameter lens or mirror or radio dish and longer-wavelength electromagnetic radiation 
D)  a smaller-diameter lens or mirror and shorter-wavelength electromagnetic radiation

Question 13

A small refracting "spyglass" telescope has an objective lens with a diameter of 2 inches.The world's largest refracting telescope at Yerkes Observatory has an objective lens with a diameter of 40 inches.Assuming that all light striking the objectives passes through them,how much larger is the light-gathering power of Yerkes than that of the spyglass?

Accepted Answer

A)  twice 
B)  40 times 
C)  80 times 
D)  400 times 
A)  twice 
B)  40 times 
C)  80 times 
D)  400 times

Question 14

As a new star evolves from cool dust and gas to a hot star,the peak wavelength of its spectrum of emitted electromagnetic radiation will:

Accepted Answer

A)  change from the infrared to the visible wavelengths. 
B)  change from the ultraviolet to the visible range. 
C)  increase from the visible to infrared wavelengths. 
D)  remain the same. 
A)  change from the infrared to the visible wavelengths. 
B)  change from the ultraviolet to the visible range. 
C)  increase from the visible to infrared wavelengths. 
D)  remain the same.

Question 15

How much heavier is a hydrogen atom than a proton?

Accepted Answer

A)  twice as heavy 
B)  1 part in 2000 
C)  2000 times heavier 
D)  A hydrogen atom is lighter than a proton. 
A)  twice as heavy 
B)  1 part in 2000 
C)  2000 times heavier 
D)  A hydrogen atom is lighter than a proton.

Question 16

Telescopes are placed in space to view distant galaxies PRIMARILY to:

Accepted Answer

A)  get closer to the observed objects. 
B)  avoid the absorption and distortion of the light or other radiations within the atmosphere of Earth. 
C)  avoid having to steer the telescope against Earth's motion. 
D)  avoid the light pollution from Earth's populated areas. 
A)  get closer to the observed objects. 
B)  avoid the absorption and distortion of the light or other radiations within the atmosphere of Earth. 
C)  avoid having to steer the telescope against Earth's motion. 
D)  avoid the light pollution from Earth's populated areas.

Question 17

In which one of the following ranges of the electromagnetic spectrum do photons have the MOST energy?

Accepted Answer

A)  infrared 
B)  visible 
C)  ultraviolet 
D)  all of them since all electromagnetic photons have the same energy 
A)  infrared 
B)  visible 
C)  ultraviolet 
D)  all of them since all electromagnetic photons have the same energy

Question 18

What percentage of the light falling on the BEST CCDs is typically wasted (does NOT contribute to the formation of the image)?

Accepted Answer

A)  1% 
B)  10% 
C)  90% 
D)  98% 
A)  1% 
B)  10% 
C)  90% 
D)  98%

Question 19

A blackbody is an idealized object in physics and astronomy that:

Accepted Answer

A)  reflects no light and emits light in a manner determined by its temperature. 
B)  reflects and emits radiation in a manner that is completely determined by its temperature. 
C)  reflects and emits light with the same intensity at all wavelengths. 
D)  does not emit or reflect any radiation. 
A)  reflects no light and emits light in a manner determined by its temperature. 
B)  reflects and emits radiation in a manner that is completely determined by its temperature. 
C)  reflects and emits light with the same intensity at all wavelengths. 
D)  does not emit or reflect any radiation.

Question 20

The wavelength of green light is about 500 nanometers.What is this length in meters?

Accepted Answer

A)  500 thousandths of a meter 
B)  500 trillionths of a meter (1 trillion = 1,000,000 million) 
C)  500 millionths of a meter 
D)  500 billionths of a meter (1 billion = 1000 million) 
A)  500 thousandths of a meter 
B)  500 trillionths of a meter (1 trillion = 1,000,000 million) 
C)  500 millionths of a meter 
D)  500 billionths of a meter (1 billion = 1000 million)

What is the one fundamental difference between X-rays and radio waves?

The BEST shape for the cross-section of a simple astronomical mirror to have in order to produce the sharpest images of very distant objects at its prime focus is:

According to modern atomic theory,light emitted by atoms originates from:

If we were to send a laser light pulse toward the Moon and some of this light were to be reflected toward Earth from retro-reflectors left on the Moon by astronauts,how long after the transmission of the initial flash would the reflected light be detected through a telescope on Earth?

How does the angular resolution of the 305-m Arecibo radio telescope in Puerto Rico compare with the angular resolution of the 10-m Keck optical telescope on Mauna Kea,Hawaii?

In the revolution that overtook physics around 1900,the assumption that Planck made in order to solve the problem concerning the spectrum of radiation emitted by a hot blackbody was that radiation was:

A refracting telescope has an objective lens of focal length 40 cm and a diameter of 10 cm,and an eyepiece of focal length 5 cm and diameter 1 cm.What is the magnifying power of this telescope?

Which type of telescope uses a lens as the MAIN optical element?

The star P Cygni (in the constellation Cygnus,the Swan)is surrounded by an extensive low-density atmosphere.It has a bright,continuous spectrum with many narrow,dark absorption lines and a few bright emission lines.The bright emission lines are produced by:

A sample of hydrogen gas is heated and produces a spectrum of bright lines.A blackbody spectrum is observed through a cooler sample of hydrogen gas.This situation also produces a line spectrum,and the locations of these lines:

Which of the following combinations of components of a telescope will produce the WORST angular resolution?

As a new star evolves from cool dust and gas to a hot star,the peak wavelength of its spectrum of emitted electromagnetic radiation will:

How much heavier is a hydrogen atom than a proton?

Telescopes are placed in space to view distant galaxies PRIMARILY to:

In which one of the following ranges of the electromagnetic spectrum do photons have the MOST energy?

What percentage of the light falling on the BEST CCDs is typically wasted (does NOT contribute to the formation of the image)?

A blackbody is an idealized object in physics and astronomy that:

The wavelength of green light is about 500 nanometers.What is this length in meters?

Discovering the Night Sky

Gravitation and the Waltz of the Planets

Formation of the Solar System and Other Planetary Systems

Exoplanets

The Terrestrial Planets and Their Moons

The Outer Planets and Their Moons

Vagabonds of the Solar System

The Sun: Our Extraordinary Ordinary Star

Characterizing Stars

The Lives of the Stars From Birth Through Middle Age

The Deaths and Remnants of Stars

The Galaxies

Cosmology

Astrobiology

Filters

Exam 3: Light and Telescopes

What is the one fundamental difference between X-rays and radio waves?

The BEST shape for the cross-section of a simple astronomical mirror to have in order to produce the sharpest images of very distant objects at its prime focus is:

According to modern atomic theory,light emitted by atoms originates from:

If we were to send a laser light pulse toward the Moon and some of this light were to be reflected toward Earth from retro-reflectors left on the Moon by astronauts,how long after the transmission of the initial flash would the reflected light be detected through a telescope on Earth?

How does the angular resolution of the 305-m Arecibo radio telescope in Puerto Rico compare with the angular resolution of the 10-m Keck optical telescope on Mauna Kea,Hawaii?

In the revolution that overtook physics around 1900,the assumption that Planck made in order to solve the problem concerning the spectrum of radiation emitted by a hot blackbody was that radiation was:

A refracting telescope has an objective lens of focal length 40 cm and a diameter of 10 cm,and an eyepiece of focal length 5 cm and diameter 1 cm.What is the magnifying power of this telescope?

Which type of telescope uses a lens as the MAIN optical element?

The star P Cygni (in the constellation Cygnus,the Swan)is surrounded by an extensive low-density atmosphere.It has a bright,continuous spectrum with many narrow,dark absorption lines and a few bright emission lines.The bright emission lines are produced by:

A sample of hydrogen gas is heated and produces a spectrum of bright lines.A blackbody spectrum is observed through a cooler sample of hydrogen gas.This situation also produces a line spectrum,and the locations of these lines:

Which of the following combinations of components of a telescope will produce the WORST angular resolution?

As a new star evolves from cool dust and gas to a hot star,the peak wavelength of its spectrum of emitted electromagnetic radiation will:

How much heavier is a hydrogen atom than a proton?

Telescopes are placed in space to view distant galaxies PRIMARILY to:

In which one of the following ranges of the electromagnetic spectrum do photons have the MOST energy?

What percentage of the light falling on the BEST CCDs is typically wasted (does NOT contribute to the formation of the image)?

A blackbody is an idealized object in physics and astronomy that:

The wavelength of green light is about 500 nanometers.What is this length in meters?

Discovering the Night Sky

Gravitation and the Waltz of the Planets

Formation of the Solar System and Other Planetary Systems

Exoplanets

The Terrestrial Planets and Their Moons

The Outer Planets and Their Moons

Vagabonds of the Solar System

The Sun: Our Extraordinary Ordinary Star

Characterizing Stars

The Lives of the Stars From Birth Through Middle Age

The Deaths and Remnants of Stars

The Galaxies

Cosmology

Astrobiology

Filters