ASTR 1346 EXAM 1 QUESTIONS AND
ANSWERS 100% PASS 2026/2027
The Electromagnetic Spectrum - ANS Visible light is the particular type of electromagnetic
radiation --- to which our eyes happen to be sensitive.
There is invisible EM radiation, which goes undetected by our eyes. - ANS radio, infrared,
ultraviolet, x rays and gamma rays
The only characteristic distinguishing one from another is.. - ANS wavelength or frequency.
Where do these radiations travel through? - ANS All these radiation travel with the speed of
light
All these radiation including visible light collectively make - ANS electromagnetic spectrum.
Temperature Vs. Energy: Temperature - ANS Hot objects, high energy, high frequency, (low
wavelength) x-rays, gamma rays
Temperature Vs. Energy: Energy - ANS Cold objects, low energy, low frequency, (low
wavelength) infrared, radio waves, ect..
2026/2027 ALLRIGHTS RESERVED 1
, Spectrum: Split of light into its component wavelengths (colors). - ANS • Spectroscopy --
Analysis/study of spectrum• Instrument used --- spectroscope (a slit, prism and screen)•
Research instrument -- spectrograph or spectrometer (a telescope; a dispersing device (e.g
prism or diffraction grating); detector)
The diffraction grating - ANS consists of a flat glass plate in the surface of which hasbeen
ruled with diamond, equidistant parallel straight lines which may be as closes 1000 per mm.
Relationship in Absorption and Emission Lines of Spectrum - ANS A given atom/gas absorbs
and emits the SAME frequencies (wavelengths) of electromagnetic radiation.• In other words,
any given gas produces an emission line spectrum when it is hotter, and an absorption line
spectrum if it is colder and between you (your spectrograph) and a continuous light source.
continuous spectrum - ANS the emission of a continuous range of frequencies of
electromagnetic radiation (have no spectral lines)
ABSORPTION SPECTRUM - ANS Signature wavelengths appear as dark lines on an otherwise
continuous rainbow. Lines appears dips in the intensity versus wavelength graph.(Absorption
lines are dark)
EMISSION SPECTRUM - ANS Signature wavelengths appear as bright lines on an otherwise
black background. Lines appears peaks in the intensity versus wavelength graph.(Emission lines
are bright)
The Spectrum Of Sun - ANS Sun's spectrum contains absorption lines due to Earth's
atmosphere as well as the Sun's outer layer of cooler atmosphere
Why it is important to study spectra? - ANS
2026/2027 ALLRIGHTS RESERVED 2
ANSWERS 100% PASS 2026/2027
The Electromagnetic Spectrum - ANS Visible light is the particular type of electromagnetic
radiation --- to which our eyes happen to be sensitive.
There is invisible EM radiation, which goes undetected by our eyes. - ANS radio, infrared,
ultraviolet, x rays and gamma rays
The only characteristic distinguishing one from another is.. - ANS wavelength or frequency.
Where do these radiations travel through? - ANS All these radiation travel with the speed of
light
All these radiation including visible light collectively make - ANS electromagnetic spectrum.
Temperature Vs. Energy: Temperature - ANS Hot objects, high energy, high frequency, (low
wavelength) x-rays, gamma rays
Temperature Vs. Energy: Energy - ANS Cold objects, low energy, low frequency, (low
wavelength) infrared, radio waves, ect..
2026/2027 ALLRIGHTS RESERVED 1
, Spectrum: Split of light into its component wavelengths (colors). - ANS • Spectroscopy --
Analysis/study of spectrum• Instrument used --- spectroscope (a slit, prism and screen)•
Research instrument -- spectrograph or spectrometer (a telescope; a dispersing device (e.g
prism or diffraction grating); detector)
The diffraction grating - ANS consists of a flat glass plate in the surface of which hasbeen
ruled with diamond, equidistant parallel straight lines which may be as closes 1000 per mm.
Relationship in Absorption and Emission Lines of Spectrum - ANS A given atom/gas absorbs
and emits the SAME frequencies (wavelengths) of electromagnetic radiation.• In other words,
any given gas produces an emission line spectrum when it is hotter, and an absorption line
spectrum if it is colder and between you (your spectrograph) and a continuous light source.
continuous spectrum - ANS the emission of a continuous range of frequencies of
electromagnetic radiation (have no spectral lines)
ABSORPTION SPECTRUM - ANS Signature wavelengths appear as dark lines on an otherwise
continuous rainbow. Lines appears dips in the intensity versus wavelength graph.(Absorption
lines are dark)
EMISSION SPECTRUM - ANS Signature wavelengths appear as bright lines on an otherwise
black background. Lines appears peaks in the intensity versus wavelength graph.(Emission lines
are bright)
The Spectrum Of Sun - ANS Sun's spectrum contains absorption lines due to Earth's
atmosphere as well as the Sun's outer layer of cooler atmosphere
Why it is important to study spectra? - ANS
2026/2027 ALLRIGHTS RESERVED 2
