Astronomy Ch 3-5

The number of waves passing the observer per second is: 

• the energy in milliwatts. 

• the amplitude in nm. 

• the period in seconds.

• the wavelength in angstroms.

• the frequency in hertz.

Which of these is constant for all types of electromagnetic radiation in space? 

• amplitude

• energy

• speed

• frequency

• wavelength

Light waves differ fundamentally from water or sound waves because: 

• they do not require a material medium for transmission.

• they have many different wavelengths.

• they all have the same energy.

• they can only travel at one speed, regardless of the medium.

• the energy of all light waves is constant.

Of all EM waves, the ones carrying the least energy per photon are:

• gamma rays.

• ultraviolet rays

• visible light

• microwaves

• radio waves.

The visible waves carrying the most energy appear to the human eye as:

• red

• orange

• green

• blue

• violet

The frequency at which a block body's intensity peaks depends directly on its:

• radius

• mass

• magnetic fields

• temperature

• direction of motion.

If a light source is approaching you, you will observe:

• an apparent red shift of its spectral lines.

• that its light has become much bluer in color.

• that all of its spectral lines have become shorter in wavelength.

• that the amplitude of its waves have increased.

• that the speed of its photons have increased.

Typical stellar spectra appear as:

• a series of bright, colored lines

• an unbroken rainbow of colors.

• a rainbow, but with some dark lines mixed in.

• a rainbow with some bright lines on top of the continuum.

• a very red shifted rainbow due to the expansion of the universe.

The three laws dealing with the creation of various spectra are due to:

• Newton

• Fraunhofer

• Kirchoff

• Bohr

• Einstein

Why are most large telescopes reflectors, not refractors?

• Large lenses deform under their own weight, but mirrors can be supported.

•  Large mirrors need only one optical surface, achromats four surfaces to grind.

• Reflectors do not suffer from chromatic aberration like refractors do.

• Large, very clear lenses are harder to cast than more tolerant mirror blanks.

• All of the above are correct.