EXMA 2 ASTRO

You record the spectrum of a star and find that the calcium absorption line, whose rest wavelength is 393.3 nm, has an observed wavelength of 394.0 nm. What is the radial velocity of this star? a. 500 km/s c. 5 km/s b. 50 km/s d. 0.5 km/s

a. 500 km/s

Using the figure below, which type of electromagnetic wave has a frequency of approximately 3.0 x10^17 Hz? a. X-rays c. microwave b. infrared d. radio

a. X-rays

Which formula denotes how the speed of light is related to its wavelength and frequency? a. c = λf c. c = f/λ b. c = λ/f d. c = 1/λf

a. c = λf

The fact that the speed of light is constant (as it travels through a vacuum) means that: a. photons with longer wavelengths have lower frequencies. b. radio wave photons have shorter wavelengths than gamma-ray photons. c. X-rays can be transmitted through the atmosphere around the world. d. All of the above are true.

a. photons with longer wavelengths have lower frequencies.

The part of the human eye that acts as the detector is the: a. retina. c. rods. b. pupil. d. cones.

a. retina

Detecting a planet around another star using the transit method is difficult because: a. the planet must pass directly in front of the star. b. the planet must have a rocky composition. c. the star must be very dim. d. the star must be moving with respect to us.

a. the planet must pass directly in front of the star.

The Voyager 1 spacecraft is currently 16.5 billion km from Earth and heading out of our Solar System. How long does it take radio messages from Voyager 1 to reach us? a. 1.5 days b. 15 hours c. 1.5 weeks d. 15 minutes

b. 15 hours

The light-gathering power of a 4-meter telescope is than that of a 2-meter telescope. a. 8 times larger b. 4 times larger c. 16 times smaller d. 2 times smaller

b. 4 times larger

Light with a wavelength of 600 nm has a frequency of: a. 5.0x10^6 Hz. c. 5.0x10^11 Hz. b. 5.0x10^14 Hz. d. 2.0x10^15 Hz.

b. 5.0x10^14

How does the speed of light traveling through a medium (such as air or glass) compare to the speed of light in a vacuum? a. It is the same as the speed of light in a vacuum. b. It is always less than the speed of light in a vacuum. c. It is always greater than the speed of light in a vacuum. d. Sometimes it is greater than the speed of light in a vacuum, and sometimes it is less, depending on the medium.

b. It is always less than the speed of light in a vacuum

The speed of light was first determined by which scientist? a. Galileo d. Newton b. Rømer e. Einstein c. Kepler

b. Rømer

The light-year is a unit of: a. time. c. speed. b. distance. d. energy.

b. distance

Which of the following lists different types of electromagnetic radiation in order of increasing wavelength? a. radio waves, infrared, visible, ultraviolet, X-rays b. gamma rays, ultraviolet, visible, infrared, radio waves c. gamma rays, X-rays, infrared, visible, ultraviolet d. X-rays, infrared, visible, ultraviolet, radio waves e. radio waves, ultraviolet, visible, infrared, gamma rays

b. gamma rays, ultraviolet, visible, infrared, radio waves

Using the figure below, which type of electromagnetic wave has a wavelength of approximately 10-5 meter? a. X-rays c. microwave b. infrared d. radio

b. infrared

Before CCDs were invented, what was the device most commonly used for imaging with optical telescopes? a. Polaroid cameras c. high-speed film b. photographic glass plates d. video cameras

b. photographic glass plates

What are two properties shared between the eye and all other astronomical detectors? a. integration time and wavelength sensitivity b. quantum efficiency and integration time c. wavelength sensitivity and signal strength d. quantum efficiency and signal strength

b. quantum efficiency and integration time

A prism is able to spread white light out into a spectrum of colors based on the property of: a. reflection. c. scattering. b. refraction. d. interference.

b. refraction.

Why do reflecting telescopes usually have a secondary mirror in addition to a primary mirror? a. to increase the light-gathering power b. to make the telescope shorter c. to increase the focal length d. to combat chromatic aberration

b. to make the telescope shorter

What is the best method commonly used to detect Earth-sized extrasolar planets with the telescopes and instrumentation that exist today? a. Doppler shift b. transit c. direct imaging d. microlensing

b. transit

The speed of light in a vacuum is: a. 300,000 m/s. d. 300,000,000 mph. b. 300,000 mph. e. infinite. c. 300,000 km/s.

c. 300,000 km/s.

As wavelength increases, the energy of a photon_______ and its frequency____________ a. increases; decreases c. decreases; decreases b. increases; increases d. decreases; increases

c. decreases; decreases

Cameras that use adaptive optics provide higher spatial resolution images primarily because: a. they operate above Earth's atmosphere. b. they capture infrared light, which has a longer wavelength than visible light. c. deformable mirrors are used to correct the blurring due to Earth's atmosphere. d. composite lenses correct for chromatic aberration.

c. deformable mirrors are used to correct the blurring due to Earth's atmosphere.

Three stars are found to have been formed from a molecular cloud. How many high density fragments must have existed in the cloud prior to star formation? a. exactly three c. three or more b. only one d. none

c. three or more

Which properties of light changes in a refractive medium? a. wavelength c. wavelength and speed b. frequency, speed, and wavelength d. speed

c. wavelength and speed

Which telescope would collect 100 times more light than a 1-meter telescope? a. 100-meter telescope c. 30-meter telescope b. 50-meter telescope d. 10-meter telescope

d. 10-meter telescope

How much mass was there in the protoplanetary disk out of which the planets formed compared to the mass of the Sun? a. 50 percent c. 5 percent b. 10 percent d. <1 percent

d. <1 percent

Which of the following photons carry the least amount of energy? a. a blue photon of the visible spectrum, whose wavelength is 450 nm b. an infrared photon, whose wavelength is 10-5 meter c. a red photon in the visible spectrum, whose wavelength is 700 nm d. a microwave photon, whose wavelength is 10-2 meter

d. a microwave photon, whose wavelength is 10-2 meter

As a beam of light travels from one medium to another, the change in direction of the beam of light depends on: a. the wavelength of the light. b. the index of refraction of the medium through which it is traveling. c. the index of refraction of the medium into which it is moving. d. all of the above

d. all of the above

Whether or not a planet is composed mostly of rock or gas is set by: a. its mass. c. the distance from the star that it orbits. b. its temperature. d. all of the above

d. all of the above

Both reflecting and refracting telescopes suffer from: a. chromatic aberration. b. diffraction effects and chromatic aberration. c. greater increase in weight for a given increase in aperture. d. diffraction effects.

d. diffraction effects.

Astronomers have used radial velocity monitoring to discover: a. extrasolar planetary systems that are similar to our own Solar System. b. Earth-sized planets around other stars. c. Earth-sized planets at distances of 10 AU from their parent stars. d. extrasolar planetary systems that contain more than one planet.

d. extrasolar planetary systems that contain more than one planet.

Arrays of radio telescopes can produce much better resolution than single-dish telescopes because they work based on the principle of: a. reflection. c. diffraction. b. refraction. d. interference.

d. interference.

The most important improvement that photography provides over naked-eye observations is: a. it is possible to observe a larger field of view with photographic plates. b. the quantum efficiency is higher for photographic plates. c. the image resolution is much better for photographic plates. d. it is possible to detect fainter objects with the use of photographic plates.

d. it is possible to detect fainter objects with the use of photographic plates.

Which of the following portions of the electromagnetic spectrum has the highest energies? Gamma Rays Infrared Visible All are the same.

gamma

Region A of a terrestrial world has 20 impact craters. Region B, which has the same size as Region A, has 5 impact craters. Which region is likely to be older? Region A Region B

A

Which of the following layers of the Earth's interior should be least dense? Crust Inner Core Mantle Outer Core

A

Which of the following portions of the electromagnetic spectrum has the fastest speeds? Gamma Rays Infrared Visible All are the same.

All are the same

Which of the following statements is FALSE? Planetary systems begin as a disk of material around a protostar. Planetesimals accrete material to become planets. All the planetesimals in our Solar System have become planets.

All the planetesimals in our Solar System have become planets.

Which of the following statements about light waves is correct? As the frequency increases, the wavelength decreases. As the frequency increases, the wavelength increases. Changing the frequency has no effect on wavelength.

As the frequency increases, the wavelength decreases.

What should be true about Earth's internal heat? It is produced by the magnetic field. It would have been greater long ago when Earth was young. It currently is produced by differentiation.

B

Which of the following layers of the Earth's interior should be the hottest? Crust Inner Core Mantle Outer Core

B

Which color star would be the hottest? Blue White Red Yellow

Blue

Which of the following layers of the Earth's interior is composed of liquid metal? Crust Inner Core Mantle Outer Core

D

As the protostar collapses, its density ______ and the temperature ________, so the brightness _________. Decreases, decreases, decreases Increases, increases, increases

Increases, increases, increases

For red light and blue light to have the same total amount of energy, which of the following must be true? More blue photons are present. More red photons are present. Both colors are present in equal amounts.

More red photons are present.

For red light and blue light to have the same total amount of energy, which of the following must be true? More blue photons are present. More red photons are present. Both colors are present in equal amounts.

More red photons are present.

If a star shows a redshift in its spectrum, does that mean that the star's color has turned red? Yes No

No

Why do astronomers use space telescopes? To be closer to the objects they observe. To minimize the effects of the atmosphere.

To minimize the effects of the atmosphere