profc.jpg (13600 bytes)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. Your best bet for finding a black hole is to search for

     a. a region of space where nothing can be seen  

     b. a source of x-ray emission

     c. a cool star

     d. a molecular cloud

     e. a pulsar


2. The Sun will end its life as

     a. a neutron star      b. a pulsar      c. a black hole     d. a brown dwarf     e. none of the above


3. A nova is powered by

     a. gravitational collapse

     b. conversion of H to He

     c. a black hole

     d. a main sequence star

     e. rotation


4. When a white dwarf with a mass just slightly smaller than 1.4MSun accretes more gas

     a. it becomes a hot star

     b. it becomes a red giant

     c. it can become a supernova

     d. it becomes a planetary nebula

     e. none of the above


5. Which of the following has the smallest diameter?

     a. a hot star    b. a cool star     c. a white dwarf       d. a neutron star       e. Earth


6. Which of the following can escape from inside the event horizon of a black hole?

     a. particles of matter         b. particles of antimatter         c. quarks         d. gamma rays         e. none of the above


7. Supernovae occur when

    a. the core of a star blows up

    b. the outer layers of a star collapse onto the core, and explode in the shock wave sent back out from the impact

    c. the outer layers of a star fall into a black hole, releasing a lot of energy

    d. a catastrophe in the stellar nucleus sends a heat pulse out through the star

    e. the neutrinos escape from the core of the star, causing it to collapse


8. Massive stars cannot burn iron because

    a. they cannot form iron to burn

    b. iron does not react with other elements

    c. they cannot reach high enough temperatures to burn iron

    d. when iron burns, it removes energy and causes the star to collapse

    e. rather than buring in fusion, the iron nucleus splits into lighter elements