Astr 3- HW 3

A telescope's ability to separate different sources of light is referred to as its—

•  

  resolving power

• objective

• refraction

• magnification

Electromagnetic radiation penetrates the earth’s atmosphere in what portions of the spectrum?

• wavelengths

• ultraviolet & radio

• visible & radio, a little infrared

• gamma rays & radio

In which spectral region does the Sun emit most of its energy?

• visible

• radio

• gamma ray

• infrared

Light is a radiant form of energy that travels through space in the form of oscillating —

•  heat waves.

• electric & magnetic fields.

•  neutral particles.

•  gases.

The speed of light is —

•  300,000 mph

•  300,000 km/s

•  30,000 mph

•  30,000 km/s

What determines the color of the Great Nebula in Orion?

•  Its temperature causes its continuous spectrum to peak in the red (Wien law)

•  It is the wavelength corresponding to the energy difference between the 3rd and 2nd energy levels of the hydrogen atom

•  It would actually appear yellow, except that it is Doppler-shifted into the red by a high velocity away from us

What distinguishes the elements, i.e., hydrogen from helium, etc.?

•  

  The number of electrons in the atom

•  

  The number of protons in the atom

•  

  The wavelength of light emitted by the atom

•  

  The number of neutrons in the atom

What is the relation between wavelength & frequency? Frequency is —

•  

  proportional to the wavelength squared

•  

  inversely proportional to wavelength

•  

  independent of wavelength

•  

  inversely proportional to the wavelength squared

What property of light is responsible for the rainbow caused by the dispersion of light by the grooves on a DVD?

•  

  diffraction

•  

  reflection

•  

  refraction

•  

  Stefan-Boltzmann law

Which has the higher surface temperature, a red star or a blue star?

•  

  Red star

•  

  Cannot be determined with current information

•  

  All stars have the same surface temperature

•  

  Blue star