practice questions Flashcards
(10 cards)
Which of the following correctly matches the term with the process or scenario described? Select ALL that apply.
a) Absorption: The solar photosphere absorbs light coming from the core and produces a blackbody spectrum
b) Reflection: Light enters water and exits at a different angle
c) Transmission: A photon travels through a cloud of hot gas without interacting with any atom or electron
d) Emission: The solar photosphere emits a blackbody glow because it is hot
c, d
✓ Transmission: A photon travels through a cloud of hot gas without interacting with any atom or electron
✅ Correct. This is exactly what transmission means — light passing through a medium without being absorbed or scattered.
✓ Emission: The solar photosphere emits a blackbody glow because it is hot
✅ Correct. The solar photosphere is a dense, opaque gas, so it emits thermal radiation, which is a form of emission.
Which of the following statements about light are correct? Select ALL that apply.
a) Blue light has a higher frequency than red light.
b) All visible light has the same wavelength, which is why we can see it.
c) The colour of light is related to its wavelength.
d) Light with a longer wavelength has a lower frequency.
e) The speed of light impacts its colour.
a, d
✓ Blue light has a higher frequency than red light
✅ Correct. Blue = shorter wavelength = higher frequency.
✓ Light with a longer wavelength has a lower frequency
✅ Correct. This follows from the equation:
c=λ⋅f
Which of the following describe a perfect blackbody? Select ALL that apply.
a) An object that reflects all light that hits it perfectly.
b) An object that emits light at every wavelength but at different intensities.
c) An object with a spectrum identical to that of the Sun.
d) An object that emits light at every wavelength with equal intensity.
e) An object whose spectrum depends only on its temperature.
b, e
✓ An object that emits light at every wavelength but at different intensities
✅ Correct. A blackbody emits radiation across all wavelengths, but intensity varies with wavelength and temperature (Planck curve).
✓ An object whose spectrum depends only on its temperature
✅ Correct. This is core to the definition of blackbody radiation. A perfect blackbody’s spectrum is shaped only by its temperature — not by material or composition.
Two objects, A and B, are both perfect blackbodies. Object and A is hotter than Object B. Which of the following statements are TRUE? Select ALL that apply.
a) Object B emits more light at redder wavelengths since it is cooler than Object A
b) Both objects emit light across the entire electromagnetic spectrum
c) Object A’s emission peaks in the ultraviolet, while Object B’s emission peaks in the infrared
d) Object A emits more energy at every wavelength than Object B
e) Object A is brighter than Object B
b, d, e
✓ Both objects emit light across the entire electromagnetic spectrum
✅ Correct. All perfect blackbodies do — intensity varies, but emission spans all wavelengths.
✓ Object A emits more energy at every wavelength than Object B
✅ Correct. From the Planck curve and Stefan-Boltzmann Law, hotter objects outshine cooler ones at all wavelengths.
✓ Object A is brighter than Object B
✅ Correct. Because total brightness is proportional to T^4, and A has higher temperature.
Which of the following are examples of the impact of tidal forces? Select ALL that apply.
a) Volcanic activity on Jupiter’s moon Io is caused by stretching and squeezing from Jupiter’s gravity.
b) The Moon is at the perfect distance to create total solar eclipses.
c) Earthquakes and volcanic activity happen on Earth due to its hot liquid core.
d) An exoplanet orbiting a distant star always keeps the same side facing the star, causing that side to become extremely hot, while the other side stays cold in constant darkness.
e) The Moon’s rotational period matches its orbital period.
a, d, e
✓ Volcanic activity on Jupiter’s moon Io is caused by stretching and squeezing from Jupiter’s gravity.
✅ Correct. This is a textbook case of tidal heating caused by varying gravitational pull — Io’s interior is flexed by Jupiter.
✓ An exoplanet orbiting a distant star always keeps the same side facing the star…
✅ Correct. This is tidal locking, where gravitational forces gradually synchronize the planet’s rotation and orbit so it always shows the same face — a direct result of tidal forces.
✓ The Moon’s rotational period matches its orbital period.
✅ Correct. This is the classic example of tidal locking — tidal forces from Earth locked the Moon’s rotation to match its orbit.
Which of the following lists orders the objects from SMALLEST to LARGEST peak wavelength of blackbody radiation?
a) A Red Star, a Blue Star, Fire, Ice, Human
b) Ice, Human, Fire, a Red Star, a Blue Star
c) A Blue Star, a Red Star, Fire, Human, Ice
d) Ice, Human, Fire, a Red Star, a Blue Star
e) Human, Ice, Fire, a Blue Star, a Red Star
b
Which of these correctly orders light in the electromagnetic spectrum from SHORTEST wavelength to LONGEST wavelength?
a) Ultraviolet, X-ray, Visible, Radio, Infrared
b) Infrared, Radio, Visible, Ultraviolet, X-ray
c) Radio, Infrared, Visible, Ultraviolet, X-ray
d) X-ray, Ultraviolet, Visible, Infrared, Radio
e) Ultraviolet, X-ray, Visible, Infrared, Radio
d) X-ray, Ultraviolet, Visible, Infrared, Radio
You collect the spectra of two stars, Star A and Star B (shown in the diagram). Star B peaks at redder wavelengths and Star A’s curve is higher. Based on these spectra, what can we say about these stars?
Star A is brighter in infrared than Star B
Below, M represents mass and R represents radius. Which of these planets will have a greater escape velocity at its surface?
a) A planet of mass M/2 and radius R/2
b) A planet of mass M and radius R
c) A planet of mass M/2 and radius R
d) A planet of mass M/2 and radius 2R
e) A planet of mass M and radius R/2
e) A planet of mass M and radius R/2
Which of the following types of electromagnetic radiation travels slowest in a vacuum?
a) Infrared Light
b) Radio Waves
c) Visible Light
d) They all travel at the same speed
e) X-Rays
d) They all travel at the same speed
