Use these questions to test your understanding. If you get them wrong, you will be linked back to the relevant part of the notes.
Be sure you study them thoroughly (don't just get a quick fix for your mistake) so your overall understanding is improved.
1. When you are listening to the radio, you are hearing
a. sound waves b.radio waves c. amplitude modulation d. frequency modulation
2. These days, astronomers depend on ____________ for obtaining new observations of photons from the stars
a. their eyes b. refracting telescopes c. electronic detectors d. discovering notebooks of previous astronomers
3. Astronomers like big telescopes because
a. big telescopes make them feel important
b. big telescopes can see smaller details (have higher resolution)
c. they actually prefer small ones because they are easier to move around
d. big telescopes can carry heavier instruments than small ones
4. Observatories are put in in space
a. to get them closer to the stars
b. so they can observe night and day
c. because they can be pointed more accurately there
d. to get above bad weather so observations are not interrupted by clouds
e. to get above the atmosphere and its absorption of photons
5. Gravity is an important force in shaping the Universe because
a. it is the strongest force we know
b. it works well over long distances and there is no antigravity
c. actually, it does not play much of a role off the surface of the earth
d. it holds the protons and neutrons in the nucleus of an atom
e. it is the only inverse r squared force
6. The "strong nuclear force"
a. affects the motions of the planets because it is the strongest force
b. is actually the second strongest force
c. has little direct effect on the motions of the planets because it is so short range
d. holds the electrons in orbit around the atom nucleus
e. holds atoms together to make large objects like planets
7. "anti matter"
a. is repelled by the gravitational field of the earth
b. is a prediction of physics that has not been found yet
c. is the material some of the other planets might be made of
e. is an invention in science fiction stories
8. The most basic building blocks of matter that we know about are
a. protons, neutrons, and electrons b. photons c. quarks d. antiprotons and antineutrons e. neutrinos
9. The electromagnetic force does not dominate interactions between celestial bodies because
a. it is too weak b. it acts only over short distances c. it needs magnetic materials to be effective
d. positive charges largely cancel the effects of negative ones e. actually, it does dominate such interactions