Deck 3: Radiation: Information from the Cosmos

Question 1

You would perceive a change in a visible light wave's amplitude as a change in its color.

Answer 1

False

Question 2

As white light passes through a prism,the red (longer)wavelengths bend less than the blue (shorter)wavelengths,so forming the rainbow of colors.

Answer 2

True

Question 3

A blue star has a higher surface temperature than a red star.

Answer 3

True

Question 4

Wave energy can only be transmitted through a material medium.

Question 5

The greater the disturbance of the medium,the higher the amplitude of the wave.

Question 6

X-rays travel at a greater speed than radio waves.

Question 7

If a new wave arrives on shore every two seconds,then its frequency is 2 Hz.

Question 8

In blackbody radiation,the energy is radiated uniformly in every region of the spectrum,so the radiating body appears black in color.

Question 9

An observer will measure the wavelength of waves emanating from a source that is moving away as longer than it really is.

Question 10

Gamma Rays are a type of electromagnetic radiation.

Question 11

The frequency of a water wave gives us its height.

Question 12

Wein's law relates the peak wavelength of the blackbody to its size.The larger the black body,the shorter its peak wavelength.

Question 13

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

Question 14

Doubling the temperature of a black body will double the total energy it radiates.

Question 15

While gravity is always attractive,electromagnetic forces are always repulsive.

Question 16

Observations in the X-ray portion of the spectrum are routinely done from the surface of the Earth.

Question 17

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

Question 18

Radio waves,visible light,and X-rays are all a type of electromagnetic radiation.

Question 19

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

Question 20

According to Wein's law,the higher the surface temperature of a star,the redder its color.

Question 21

The Earth's ionosphere partially blocks which form of electromagnetic radiation?

A) gamma rays
B) ultraviolet
C) visible light
D) infrared
E) radio

Question 22

Which form of electromagnetic radiation would be blocked in the stratosphere by ozone?

A) cosmic rays
B) ultraviolet
C) visible light
D) infrared
E) microwaves

Question 23

The number of waves passing the observer per second is:

A) the wavelength in angstroms.
B) the amplitude in nm.
C) the frequency in Hertz.
D) the period in seconds.
E) the energy in milliwatts.

Question 24

The temperature scale that places zero at the point where all atomic and molecular motion ceases is:

A) Fahrenheit.
B) Celsius.
C) Kelvin.
D) centigrade.
E) Ransom.

Question 25

Which statement gives the relationship between the waves in the electric and magnetic fields in an electromagnetic wave?

A) They are in phase and parallel with each other in space.
B) They are 90 degrees out of phase but parallel in space.
C) They are in phase but perpendicular to each other in space.
D) They are 180 degrees out of phase and random in their inclinations to each other.
E) They are in phase but opposite in direction of motion.

Question 26

The hottest objects with temperatures in the millions of Kelvins,give off most of their radiation in which part of the electromagnetic spectrum?

A) visible
B) radio
C) ultraviolet
D) X-ray
E) gamma ray

Question 27

Electromagnetic radiation:

A) can only travel in a dense medium.
B) has only the properties of waves.
C) can behave both as a wave and as a particle.
D) is the same as a sound wave.
E) has nothing in common with radio waves.

Question 28

Electromagnetic radiation with a wavelength of 700 nm would be:

A) X-rays.
B) red light.
C) violet light.
D) ultraviolet light.
E) microwaves.

Question 29

Both sound waves and electromagnetic radiation:

A) travel at the speed of light.
B) require a medium to move through space.
C) can move through space without a medium.
D) transfer energy.
E) are transverse waves.

Question 30

Consider this diagram.Which statement is true?

A) The amplitude is 4.
B) The amplitude is 6.
C) The amplitude is 8.
D) The amplitude is 12.
E) The amplitude cannot be determined from this diagram.

Question 31

Which form of electromagnetic radiation is absorbed by carbon dioxide and water vapor in our atmosphere?

A) visible light
B) ultraviolet
C) infrared
D) radio
E) gamma rays

Question 32

What does the phenomenon of diffraction demonstrate?

A) the wave nature of light
B) the polarization of light waves
C) the quantization of atomic orbitals
D) the particle nature of the photon
E) the process of ionization

Question 33

A wave's velocity is the product of the:

A) frequency times the period of the wave.
B) period times the energy of the wave.
C) amplitude times the frequency of the wave.
D) frequency times the wavelength of the wave.
E) amplitude times the wavelength of the wave.

Question 34

Consider this diagram.Which statement is true?

A) The wavelength is 4.
B) The wavelength is 6.
C) The wavelength is 8.
D) The wavelength is 12.
E) The wavelength cannot be determined from this diagram.

Question 35

Which of these is constant for ALL types of electromagnetic radiation in a vacuum?

A) amplitude
B) wavelength
C) frequency
D) velocity
E) photon energy

Question 36

What does the phenomenon of interference demonstrate?

A) the wave nature of light
B) the polarization of light waves
C) the quantization of the atomic orbitals
D) the particle nature of the photon
E) the process of ionization

Question 37

X-ray telescopes are located in orbit around the Earth because:

A) X-ray telescopes on Earth would have to be too big.
B) X-ray telescopes are cheap and easy to launch into space.
C) there are too many X-ray telescopes on Earth, so now they are put in space.
D) X-rays don't reach the surface of Earth.
E) the X-rays that come out of the telescopes are dangerous to humans.

Question 38

Of all the forms of electromagnetic radiation,the one with the lowest frequency is:

A) gamma rays.
B) ultraviolet rays.
C) visible light.
D) microwaves.
E) radio waves.

Question 39

The two forms of electromagnetic radiation that penetrate the atmosphere best are:

A) X-rays and gamma rays.
B) ultraviolet and visible light.
C) visible and infrared light.
D) visible and radio waves.
E) infrared and microwaves.

Question 40

If a wave's frequency doubles,its wavelength:

A) is halved.
B) is also doubled.
C) is unchanged, as c is constant.
D) is now 4 times longer.
E) becomes 16 times longer.

Question 41

Very hot,young stars,like those in Messier 2 emit most of their light in which part of the electromagnetic spectrum?

A) the visible
B) the X-ray
C) the ultraviolet
D) the radio
E) the infrared

Question 42

According to Wein's Law,if the surface temperature is increased by a factor of 2,its peak wavelength will:

A) increase by a factor of 2.
B) decrease by a factor of 2.
C) increase by a factor of 4.
D) decrease by a factor of 4.
E) not change; Wein's law has nothing to do with peak wavelength.

Question 43

The radiation our eyes are most sensitive to lies in the color:

A) red at 6563 Angstroms.
B) yellow-green at about 550 nm.
C) violet at 7,000 Angstroms.
D) blue at 4,321 nanometers.
E) black at 227 nm.

Question 44

Star A has a temperature 3 times that of star B.Both star A and star B are the same physical size.Which statement about star A and star B below is correct?

A) Star A is redder and dimmer than star B.
B) Star A is bluer and dimmer than star B.
C) Star A is redder and brighter than star B.
D) Star A is bluer and brighter than star B.
E) Star A and star B have the same color, but star A is brighter.

Question 45

Star A and star B have the same temperature,but star A is 5 times bigger than star B.Which statement below is correct?

A) Star A is redder and dimmer than star B.
B) Star A is bluer and dimmer than star B.
C) Star A is redder and brighter than star B.
D) Star A is bluer and brighter than star B.
E) Star A and star B have the same color, but star A is brighter.

Question 46

Star A and star B have the same temperature,but different luminosities.What can you infer about these two stars?

A) Star A must be bigger.
B) Star B must be bigger.
C) Star A must be redder.
D) Star B must be redder.
E) Nothing can be inferred from the information given.

Question 47

There are no radio telescopes in space because:

A) no one has built an antenna large enough to reach astronomical objects yet.
B) radio telescopes are too fragile and expensive to make to put into space.
C) there is too much radio noise in space, so a radio telescope won't work out there.
D) radio waves penetrate Earth's atmosphere so there is no need to put one in space.
E) you need an array, like the VLA, to detect ANY radio radiation, so it is just not realistic to put an entire array in space.

Question 48

There are no X-ray telescopes on Earth because:

A) they are too expensive to build.
B) no one has yet invented an X-ray telescope that works.
C) we can't figure out how to direct an X-ray beam through space.
D) X-rays don't penetrate Earth's atmosphere.
E) there are no astronomical objects that emit X-rays.

Question 49

At which of these Kelvin temperatures would a blackbody radiate mostly at visible wavelengths?

A) 6 K
B) 60 K
C) 600 K
D) 6000 K
E) None of these; a blackbody doesn't radiate visible light.

Question 50

The visible color of electromagnetic radiation that has the shortest wavelength is:

A) red.
B) orange.
C) green.
D) blue.
E) violet.

Question 51

The wavelength at which a blackbody radiates most depends on its:

A) radius.
B) mass.
C) magnetic fields.
D) temperature.
E) direction of motion.

Question 52

Star A has a temperature 1/4 that of star B.Both star A and star B are the same physical size.Which statement below is correct?

A) Star A is redder and dimmer than star B.
B) Star A is bluer and dimmer than star B.
C) Star A is redder and brighter than star B.
D) Star A is bluer and brighter than star B.
E) Star A and star B have the same color, but star A is brighter.

Question 53

The total energy radiated by a blackbody depends on:

A) the fourth power of its temperature.
B) the square of its temperature.
C) the square root of its temperature.
D) the cube root of its temperature.
E) the cube of its temperature.

Question 54

Star A and star B have the same temperature,but star B is more luminous than star A.What can you infer about these two stars?

A) Star A must be bigger.
B) Star B must be bigger.
C) Star A must be redder.
D) Star B must be redder.
E) Nothing can be inferred from the information given.

Question 55

Star A has a temperature 1/2 that of star B,but star A is 5 times bigger than star B.Which statement below is correct?

A) Star A is redder and dimmer than star B.
B) Star A is bluer and dimmer than star B.
C) Star A is redder and brighter than star B.
D) Star A is bluer and brighter than star B.
E) Star A and star B have the same color, but star A is brighter.

Question 56

Star A has a temperature 1/2 that of star B,but star A is 3 times bigger than star B.Which statement below is correct?

A) Star A is redder and dimmer than star B.
B) Star A is bluer and dimmer than star B.
C) Star A is redder and brighter than star B.
D) Star A is bluer and brighter than star B.
E) Star A and star B have the same color, but star A is brighter.

Question 57

Which type of radiation can be observed well from Earth's surface?

A) gamma ray
B) X-ray
C) ultraviolet
D) visible
E) infrared

Question 58

Colors appear different to us because of their photons' different:

A) speeds.
B) amplitudes.
C) frequencies.
D) magnetic fields.
E) polarization.

Question 59

What is true of a blackbody?

A) It appears black to us, regardless of its temperature.
B) Its energy is not a continuum.
C) Its energy peaks at the wavelength determined by its temperature.
D) If its temperature doubled, the peak in its curve would be doubled in wavelength.
E) It has a complete absence of thermal energy.

Question 60

Very low temperature molecular clouds emit most of their light in which part of the electromagnetic spectrum?

A) the visible
B) the X-ray
C) the ultraviolet
D) the radio
E) the infrared

Question 61

To see the Sun's hot corona (a temperature of 1,000,000 K),which part of the electromagnetic spectrum should one observe?

A) the visible
B) the X-ray
C) the ultraviolet
D) the radio
E) the infrared

Question 62

If a light source is approaching you at a speed very close to the speed of light,it will appear:

A) redder than it is.
B) bluer than it is.
C) brighter than it is.
D) fainter than it is.
E) lower temperature than it is.

Question 63

A dim,young star like Herbig-Haro 68 emits most of its light in which part of the electromagnetic spectrum?

A) the visible
B) the X-ray
C) the ultraviolet
D) the radio
E) the infrared

Question 64

Light that has all the electrical fields vibrating in the same plane is said to be ________.

Question 65

The Doppler Effect is a phenomenon that allows one to measure an object's:

A) temperature.
B) radius.
C) radial motion.
D) tangential motion.
E) chemical composition.

Question 66

Stefan's Law says:

A) the hotter a star's surface, the bluer it looks to us.
B) E = mc².
C) the energy radiated by a blackbody is proportional to T³.
D) that if the Sun's temperature were doubled, it would give off 16X more energy.
E) that doubling the star's temperature would also double its peak wavelength.

Question 67

The distance between two successive wave crests is the ________ of a wave.

Question 68

The light from an object moving tangentially (to your left or right)will exhibit:

A) a blueshift.
B) a redshift.
C) a shift in peak wavelength towards the red.
D) a shift in peak wavelength towards the blue.
E) no shift.

Question 69

Stars like our Sun emit most of their light in which part of the electromagnetic spectrum?

A) the visible
B) the X-ray
C) the ultraviolet
D) the radio
E) the infrared

Question 70

The distance from a wave's crest to its undisturbed state is the ________.

Question 71

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

A) 3.
B) 6.
C) 9.
D) 12.
E) 81.

Question 72

A cool star like Antares would produce more ________ than visible light.

Question 73

The product of the wavelength times the frequency of a wave is its ________.

Question 74

Increasing the temperature of a blackbody by a factor of 2 will increase its energy by a factor of:

A)
B) 4.
C) 8.
D) 16.
E) 32.

Question 75

Per unit area (such as a square centimeter),a B star whose surface temperature is 10,000 K will put out how much radiation compared to an O star whose surface temperature is 30,000 K?

A) 81 times as much
B) 9 times as much
C) 1/81 as much
D) 1/9 as much
E) 1/3 as much

Question 76

If a beam of blue light has a wavelength of 400 nm is emitted by an object moving away from you at 1% of the speed of light,what wavelength would you see from this light?

A) 396 nm
B) 399 nm
C) 400 nm
D) 401 nm
E) 404 nm

Question 77

In a wave,the distance from peak to peak is called the wave's ________.

Question 78

The Sun's blackbody curve peaks in the ________ portion of the spectrum.

Question 79

As the Sun evolves into a red giant in the distant future,then according to Wien's Law:

A) most of its energy must become shorter in wavelength.
B) its peak on the Planck curve will move into the infrared.
C) its total luminosity must decrease.
D) it will disappear from the universe of visible light.
E) its light will be slowed down by its increasing mass.

Question 80

The part of the electromagnetic spectrum with the shortest wavelengths is called ________.