Chapters 3-5 Flashcard

T/F: As white light passes through a prism, the red (longer) wavelengths bend less than the blue (shorter) wavelengths, so forming the rainbow of colors.
True
T/F: Gamma Rays are a type of electromagnetic radiation.
True
T/F: Radio waves, visible light, and X-rays are all a type of electromagnetic radiation.
True
The temperature scale that places zero at the point where all atomic and molecular motion ceases is:
Kelvin
What does the phenomenon of interference demonstrate?
The wave nature of light.
The number of waves passing the observer per second is:
The frequency in Hertz.
Which of these is constant for ALL types of electromagnetic radiation in a vacuum?
Velocity
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?
396 nm
The blackbody curve of a star moving toward Earth would have its peak shifted
Toward higher energies.
T/F: As a star’s temperature increases, the frequency of peak emission also increases.
True
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?
Star A is redder and dimmer than Star B.
The total energy radiated by a blackbody depends on:
The fourth power of its temperature.
An atom that has been ionized:
Has more protons than electrons.
In Bohr’s model of the atom, electrons:
only make transitions between orbitals of specific energies.
A heavy neutral atom, such as iron, produces many spectral lines compared to light elements like hydrogen and helium. Why?
Because of the larger number of electrons and corresponding energy levels, more transitions are possible.
If a source of light is approaching us at 3,000 km/sec, then all its waves are:
Blue shifted by 1%.
T/F: To reach the Cassegrain focus, a hole must be cut in the center of the primary mirror.
True
T/F: CCD detectors gather light 10-20 times faster than the most sensitive photographic film.
True
T/F: It is much easier to build large reflectors than large refractors.
True
A major advantage of a Newtonian reflector over a refractor is:
the elimination of chromatic aberration.
The process occurring when photons bounce off a polished surface is called:
reflection.
What type of telescope is the Hubble Space Telescope?
Cassegrain
Which method of astronomical measurement is the precise measurement of brightness?
Photometry
One advantage of the Hubble Space telescope over ground based ones is that:
in orbit, it can operate close to its diffraction limit at visible wavelengths.
What is “seeing”?
a measurement of the image quality due to air stability
T/F: Optical telescopes are usually used only at night, but radio telescopes can be used day or night.
True
What is the main reason that ultraviolet astronomy must be done in space?
Earth’s atmosphere absorbs most ultraviolet wavelengths.
The detectors on the Spitzer Space Telescope were cooled to near absolute zero in order to:
prevent the infrared radiation from the instruments interfering with the infrared signals from space.
T/F: Galaxies look the same whether viewed in visible or X-ray wavelengths.
False

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