Astronomy II part 1

1.

1 point

The two forms of electromagnetic (E-M) radiation that experience the least atmospheric opacity are

visble light and infrared waves

ultraviolet and infrared waves

visible light and radio waves

mircowaves and radio waves

X ad gamma radiation

2.

1 point

Compared to the size of the Sun, stars of all types range from

0.08 to over 8,000 solar radii

0.001 to over 50,000 solar radii

0.01 to over 1,000 solar radii

0.1 to 10 solar radii

0.5 to 50 solar radii

3.

1 point

In the Kelvin scale, absolute zero lies at

273 degrees C

Both A and C are correct

-373 degrees C

Both A and B are correct

zero K

4.

1 point

Which of these is not a form of electromagnetic radiation?

DC current from your car battery

unltraviolet causing a suntan

X-rays in the doctor's office

light from your camp fire

radio signals

5.

1 point

In general, the spectral lines of molecules are

more complex than those of atoms

only absorption lines

nonexistent

the same as the atoms they contain

less complex than those of atoms

6.

1 point

Typically a granule in the photosphere is about

the size of our Moon, about 3,000 km across

the size of a city, 20-30 km across

the size of Earth, around 12,000 km across

the size of Texas, about 1,000 km across

as big as Jupiter, around 100,000 km wide

7.

1 point

Which of these is emitted when an alectron falls from a higher to lower orbital?

a neutrino

a positron

a photon

a graviton

another electron

8.

1 point

The total energy radiated by a blackbody depends on

the fourth root of its temperature

the fourth power of its temperature

the square of its temperature

the cube of its temperature

the square root of its temperature

9.

1 point

A jar filled with gas is placed directly in front of a second jar filled with gas. Using a spectroscope to look at one jar through the other you observe dark spectral lines. The jar closest to you contains

the hotter gas

the exact same gas as the other jar

gas at very high pressure

gas at the same temperature as the other jar

the cooler gas

10.

1 point

The Sun's observed spectrum is

only emission lines on a black background

a continuum with no lines, as shown by the rainbow

a continuum with emission lines

a contiuum with absorption lines

only absorption lines on a black background

11.

1 point

Granulation is the most obvious proof of solar convective energy transport

True

False

12.

1 point

Compared to a type A0 star, a type A9 star is

more massive

hotter

more luminous

cooler

bluer

13.

1 point

What is the meaning of a solar constant?

the regularity of the 11 year sunspot cycle

the amount of energy the Earth receives per unit area and unit time

the fact that the amount of hydrogen turning into helium in the core is fixed

the fact that features on the sun appear to never change

the stablity of the Sun's luminosity for as long as life has existed on Earth

14.

1 point

A star near the lower right of the H-R diagramis likely to be

hot, bright and very large

red, with low luminosity

yellow, with luminosity similar to our Sun's

red, with high luminosity

blue, with high luminosity

15.

1 point

If a wave's frequency is halved and its speed stays constant, its wavelength

is doubled

becomes 4x shorter

is now 4x longer

is also halved

is unchanged, as c is constant

16.

1 point

If the rest wavelength of a certain line is 700 nm, but we observe it at 693 nm, then

the source is receding from us at 10% of the speed of light

The source is spinning very rapidly, at 1% of the speed of light

the source of getting 1% hotter as we watch

the source is approaching us at 0.1 of the speed of light

the source is approaching us at 1% of the speed of light

17.

1 point

Two stars have the same absolute magnitude, but one lies twice as far frm Earth as the other. It will appear half as bright.

True

False

18.

1 point

Changing the electric field will have no effect on the magnetic field of a body.

True

False

19.

1 point

Which of these stars would be the hottest

M10

G2

K9

A0

B0

20.

1 point

The shower a wave's wavelength, the greater its energy

True

False

21.

1 point

The temperature of the photosphere is about

3,200 K

11,000 K

one million K

5,800 K

ten million K

22.

1 point

On the H-R diagram, white dwarfs Sirius B and Procyon B lie

at the top right

at the lower left

at the top left

at the lower right

close to the Sun, near the center

23.

1 point

On the H-R diagram, the Sun lies

At the bottom left

at the bottom right

at the top left

at the top right

about the middle of the main sequence

24.

1 point

The H-R diagram can plot

Radius vs. Mass

Apparent Magnitude vs. Spectral Classes

Radius vs. Luminosity

Temperature vs. Mass

Temperature vs. Luminosity

25.

1 point

Wave energy can only be transmitted through a material medium.

True

False

26.

1 point

The speed of the light in a vaccum is

h=E/c

not given

186,000 miles per hour

300,000,000 m/sec

768 km/h

27.

1 point

As they move through space, the vibrating electrical and magnetic fields of a light wave but move perpendicular to each other.

True

False

28.

1 point

A G2V star would be the same temperature as a G2lb star, but much smaller and less luminous

True

False

29.

1 point

What two energy transport mechanisms, in order from outside the core to the surface, are found in the Sun?

radiation, conduction

convection, conduction

radiation, convection

conduction, convection

conduction, radiation

30.

1 point

If a source of light is moving away from us at 3,000,000 m/sec, then all its waves are

not affected, as c is constant regardless of the direction of motion

blue shirted out of the visible spectrum into the ultraviolet

blue shifted by 1%

red shifted out of the visible into the infrared

red shirted by 1%

31.

1 point

In Bohr's model of the atom, electrons

move from one orbit to the next orbit in many small steps

only make transitions between orbits of specific energies

are spread uniformly through a large, positive mass

can be halfway between orbits

are not confined to specific orbits

32.

1 point

A parsec is slightly more than 200,000 AU

True

False

33.

1 point

Increasing the temperature of a blackbody by a factor of 3 will increase its energy by a factor of

9

3

12

81

6

34.

1 point

The sun's radius is one astronmical unit by definition

True

False

35.

1 point

What can be said with certainity about a red star and a blue star?

The blue star is hotter than the red star

The blue star has a greater proper motion than the red star

The red star is more maasive than the blue star

The red star has a greater radial velocity

The red star is closer to Earth than the blue star

36.

1 point

Which of these is the same for all forms of electromagnetic (E-M) radiation in a vaccum?

photon energy

frequency

speed

amplitude

wavelength

37.

1 point

On the H-R diagram, red supergiants like Betelgeuse lie

at the bottom right

at the top right

they cannot be plotted, for they are not main sequence

at the bottom left

at the top left

38.

1 point

The observed spectral lines of a star are all shifted towards the red end of the spectrum. Which statement is true?

This is an example of the photoelectric effect

The star has a radial velocity towards us

The second law of Kirchhoff explains this

The star is not rotating

This is an example of the Doppler effect

39.

1 point

What physical property of a star does the spectral type measure?

luminosity

density

composition

temperature

mass

40.

1 point

A star is 10 parsecs from Earth. Which statement is true?

The star is about 33 ly away

The star is in a different galaxy

The star's apparent magnitude is smaller than its absolute magnitude

The star's parallax is 1.0 arc seconds

The star's apparent magnitude is larger than its absolute magnetude

41.

1 point

A wave's velocity is a product of the

frequencys times the wavelength of the wave

period times the energy of the wave

amplitude times the frequency of the wave

amplitude times the wavelength of the wave

frequency times the period of the wave

42.

1 point

Most stars are single stars like our own.

True

False

43.

1 point

The outward pressure of hot gas in the Sun

is balanced by the inward gravitational pressure

is increasing the Sun's diameter

weakens the magnetic fields

is cooling the photosphere

is responsible for variations in the sunspot cycle

44.

1 point

If a new wave arrives on shore every four seconds, then its frequency is 4 Hz

True

False

45.

1 point

Medium A blocks more of a certain wavelength of radiation than medium B. Medium A has a higher

clarity

albedo

opacity

seeing

transparency

46.

1 point

Binary stars separated enough to be resolved in a telescope are called

spectroscopic binaries

astronmetic binaries

line-of-sight-binaries

visual binaries

orbital binaries

47.

1 point

Electromagnetic radiation

can only travel in dense medium

has nothing in common with radio waves

is the same as a sound wave

can behave both as a wave and as a particle

has only the properties of waves

48.

1 point

As a star's temperature increase, the frequency of peak emission also increases

True

False

49.

1 point

The frequency of a water wave gives us its height.

True

False

50.

1 point

On the H-R diggram, the bright blue stars that dominate the naked-eye sky lie

in the middle of the mian sequence

at the top right

at the lower righ

at the lower left

at the top left