Quiz3

Tom has a 4-inch refracting telescope and Steve has a 3-inch reflecting telescope. Whose telescope has a higher resolving power?

C. Tom's, because the larger the diameter, the better the resolution

In about 14,000 A.D., the North Pole of the Earth will point at star ________.

C. Vega

A warm dust cloud in which stars are forming would be best observed with a(n) _________ telescope.

C. infared

The most abundant element in the Earth's core is ___________.

D. Iron

One of the biggest problems for ground based astronomy today is

D. Light pollution makes it difficult to observe faint objects.

Van Allen belts exist in the Earth's ___________.

D. Magnetosphere

_________ and _________ are common in regions where subduction occurs.

D. Mountains, earthquakes

The Earth's atmosphere today is about 78% _____, 21% _____, and much less than 1% _____.

D. Nitrogen, oxygen, carbon dioxide and other gases

The hotter inner core of the Earth is _______ and the relatively cooler outer core is ______. A

D. Solid; liquid

Which of the following is an inherent disadvantage of radio telescopes?

D. The long wavelength of radio waves results in lower resolving power, compared to other telescopes of the same size

What is the approximate age of the Earth?

E. 4.6 billion years

The best site for placing an X-ray telescope is _________.

E. Outside the Earth's atmosphere

The two most important properties of any telescope are

E. The light gathering power and the resolving power

A compass needle points to the North Star.

FALSE

Because of the precession of the Earth's rotation axis, the Earth's rotation axis does not always point in the direction of the celestial poles.

FALSE

CCDs are widely used in astronomy because the images are easily manipulated in computers, but photographic film is actually more sensitive to photons.

FALSE

Gamma ray telescopes, such as the Fermi Gamma Ray Space Telescope, are launched into space because they are dangerous to operate on Earth.

FALSE

Greenhouse gases (water molecules and carbon dioxide) generate heat to make our Earth warm.

FALSE

Most of the modern large optical telescopes are refractors

FALSE

Oxygen is the most common element in minerals in the Earth's crust, which is why the release of gases from the crust over time has produced an atmosphere rich in oxygen today.

FALSE

Polaris is always the pole star.

FALSE

The Atlantic Ocean has existed for most of the time since the Earth's crust cooled.

FALSE

The Earth's magnetic axis is the same as its rotation axis.

FALSE

The Earth's magnetic poles will eventually reverse. This shift will also cause the seasons to reverse.

FALSE

The Earth's spin creates the day and night cycle, but does not affect the weather pattern.

FALSE

The Hubble Telescope gets much clearer images of astronomical objects than ground based telescopes because it has a much larger mirror than ground based telescopes.

FALSE

The atmospheric greenhouse effect heats the Earth in the same way that greenhouses heat the air inside.

FALSE

The central part of the Earth's core consists of iron-rich liquid.

FALSE

The design of radio telescopes is very similar to the design of refracting telescopes

FALSE

The heavier elements like iron and nickel are abundant on the Earth's surface and the silicates dominate at the center of the Earth.

FALSE

The secondary mirror in a reflecting telescope has the negative effect of creating a hole in center of the image.

FALSE

To double the light gathering power of a telescope, we need to double the diameter.

FALSE

The ______ are two doughnut-shaped rings of charged particles trapped by the Earth's magnetic field.

B. Van Allen radiation belts

A spherical rock has a density of 3 g/cm3. If another rock has the same mass but is twice as wide, its density must be _____ g/cm3.

A. 3/8

A rock has a density of 3 g/cm3. If another rock has twice as much mass but the same volume, its density must be _____ g/cm3.

A. 6

After an earthquake, an S-type seismic wave travels with a velocity of about 10 km/s and reaches another part of the Earth in about 10 minutes. How much distance has the S-type wave covered?

A. 6000 km

The best site for placing an optical telescope is _________.

A. A mountain top

The average density of the Earth is ____.

A. About 5.5 g/cm3

Ignoring the effects of the atmosphere, what is the theoretical resolution of an 8 inch telescope (about 20 cm) if you are looking at visible light with a wavelength of about 500 nm?

A. About half an arcsecond

How is the age of a rock determined?

A. By determining the ratio of argon to potassium

Why does the Moon appear bigger near the horizon?

A. Due to an optical illusion

What is a disadvantage of using a lens in a large telescope?

A. Large lenses are expensive to fabricate B. A lens has to be supported only at its edges, so the lens can sag in the middle C. Different colors of white light on passing through a lens focus at different points and result in a blurred image D. Some lens materials completely absorb short wavelengths E. All of the above<<<<<<

Analysis of volcanic emissions suggests that eruptions could be the source of all but which of the following gases in our atmosphere?

A. Oxygen

Why does plate tectonics continue to occur on Earth?

A. The Earth is still cooling from its formation. B. The Earth contains radioactive elements. C. The Earth is heated by the Sun. D. Both A and B.<<<<<

An interstellar gas is emitting 10-centimeter wavelength radiation and a nearby star is emitting 10-micrometer wavelength radiation. Which of these can you observe through an Earth-based telescope?

A. The interstellar gas

The outer core of the Earth extends out to a little over halfway to the surface of the Earth. The volume of the core is therefore about _________ the volume of the Earth.

B. 1/8

Carbon 13 is a radioactive isotope. About half of a sample decays in 6000 years. After how long would only 1/8 of the original carbon 13 be left?

B. 18,000 years

The shift of the Earth's plates due to tectonic motion is typically of the order of ______.

B. A few centimeters per year

The resolving power of a telescope is affected by the property of light called

B. Diffraction.

Why is the Earth's inner core solid?

B. Due to the tremendous pressure of overlying material

The radius of the Earth is

B. Longer at the equator

Density is calculated as

B. Mass/volume

X-rays are blocked by ________ and _________ present in the Earth's atmosphere.

B. Ozone; oxygen

Which of the following telescopes is most suitable for observing cool gas clouds?

B. Radio telescope

The ability of a telescope to show two very close objects separately is called its ________.

B. Resolving power

______ is the most important quality of an astronomical telescope.

B. Resolving power

Which space telescope is observing X-rays?

B. The Chandra Observatory

Scientists refer to the Earth as a differentiated planet because ______.

B. The material in the interior of the Earth is separated by density

A galaxy with almost no starlight but plenty of cool clouds of hydrogen gas would be best observed with a(n) _________ telescope.

B: Radio

Suppose that we have a sample of 20 atoms of radioactive potassium which decays by half every 1.3 billion years into calcium and argon at ratios of 9:1 respectively. How many atoms of calcium do you expect to find in this sample after 1.3 billion years?

C. 9

Which is the most efficient detector?

C. Charge-coupled device (CCD)

Why do stars twinkle?

C. Due to the refraction caused by atmospheric irregularities

Using ___________, scientists can use a few smaller telescopes to take images with the same resolution as a much larger telescope.

C. Interferometry

Ozone

C. Is a molecule consisting of three oxygen atoms.

The interior layer just below the crust of the Earth is called the _______.

C. Mantle

The ___-type seismic waves can travel through liquids and solids. The ___-type seismic waves can travel through solids only.

C. P; S

From the center outward, the correct order of the zones of the Earth is

C. Solid core, liquid core, mantle, crust, atmosphere

The process in which two tectonic plates meet and one slips beneath another is called _____.

C. Subduction

Charged moving particles, such as electrons, create magnetic fields.

TRUE

Extinctions and even accelerated evolution might occur during periods when the Earth's magnetic field weakens and more charged particles and cosmic rays can penetrate it.

TRUE

If Earth did not spin, the magnetic field around it would not exist.

TRUE

Olivine is the most common mineral in the Earth's mantle.

TRUE

Oxygen is the most common element in minerals in the Earth's crust.

TRUE

Precession is the slow change in direction of the Earth's rotation axis due to the gravitational interaction of the Sun and of the Moon with the Earth's equatorial bulge.

TRUE

Silicates are minerals composed of silicon and oxygen.

TRUE

The Coriolis effect arises from the Earth's rotation and causes the majority of large scale weather patterns and ocean currents.

TRUE

The Coriolis effect demonstrates that the Earth spins.

TRUE

The Hubble telescope not only observes visible light, but also observes ultraviolet light.

TRUE

The jet stream is a result of the Coriolis effect.

TRUE

Radio telescopes on Earth can observe during the daytime.

TaRUE

Some anthropological evidence for the precession of the Earth's tilt is that the passage into the Great Pyramid in Egypt points at the star Thuban, which was the pole star about 6000 years ago.

tRUE