Unit 49-59 Review

1.  The Sun produces energy from

  1. Fusion of neutrinos into helium
  2. Fusion of positrons into hydrogen
  3. Fission of hydrogen into helium
  4. Fusion of hydrogen into helium

2.  Mass

  1. Is always conserved
  2. Is conserved if there no friction
  3. Can be converted into energy

3.  The Sun is supported against the crushing force of its own gravity by

  1. Magnetic forces
  2. Its rapid rotation
  3. The force exerted by escaping neutrinos
  4. Gas pressure

4.  Which will take longer to escape from the center of the Sun

  1. Neutrinos
  2. Photons
  3. They will escape at approximately the same time

5.  1 gram of mass corresponds to

  1. 9*1013 joules
  2. 900 joules
  3. 9*10-13 joules
  4. 9*10-5 joules

6.  Fusion occurs in the Sun’s

  1. Chromosphere
  2. Corona
  3. Core
  4. Photosphere

7.  Fusion is hard to sustain here on Earth because

  1. the electric charge of protons
  2. the high temperatures required
  3. hydrogen is very scarce
  4. all of the above
  5. both a and b

8.  In the proton-proton chain, the mass of the input is ______the mass of the output.

  1. Less than
  2. Greater than
  3. Equal to

9.  Which force binds the nucleus

  1. Gravitational
  2. Electromagnetic
  3. Strong
  4. Weak

10.  Sunspots are

  1. Due to plasma interacting with magnetic field lines
  2. Less luminous in comparison to their surroundings
  3. Cooler in comparison to their surroundings
  4. All of the above

11.  The sun rotates

  1. Differentially
  2. As a solid body
  3. Due to its magnetic field

12.  Magnetic field lines play a role in

  1. Sun spots
  2. Prominences
  3. Solar flares
  4. Coronal mass ejections
  5. All of the above

13.  About how many years elapse between times of maximum solar activity?

  1. 3
  2. 5
  3. 11
  4. 33
  5. 105

14.  Parallax is

  1. Proportional to distance
  2. Proportional to distance squared
  3. Inversely proportional to distance
  4. Inversely proportional to distance squared

15.  In 50,000 years constellations will appears

  1. The same because stars are fixed
  2. Altered due to radial velocity
  3. Altered due to proper motion

16.  Given an object’s brightness we can derive

  1. The luminosity
  2. The temperature
  3. The distance
  4. All of the above
  5. None of the above

17.  When a spaceship is traveling at 99% of the speed of light (Lorentz factor = 7), an astronaut on board the ship will find that

  1. Everything on board weights 7 times more
  2. The ship is one-seventh its original length
  3. Time is slower
  4. All of the above
  5. None of the above

18.  Tom and Molly are both traveling toward each other at half the speed of light. Tom shines a flashlight at Molly, what speed will Molly measure for the light coming toward her?

  1. 0.25c
  2. 0.5c
  3. 1.0c
  4. 1.5c
  5. 2.0c

19.  Star ‘A’ radiates most strongly at 240 nm, star ‘B’ radiates most strongly at 480 nm. The temperature of star ‘A’ is

  1. Two times more
  2. Two times less
  3. Four times more
  4. Four times less

20.  Spectral types correspond to

  1. The star’s composition
  2. The star’s brightness
  3. The star’s temperature
  4. The star’s distance

21.  A star with the same color as the Sun is found to produce a luminosity 9 times larger. The radius of the star is

  1. 3 times less than the Sun
  2. 9 times greater than the Sun
  3. 3 times greater than the Sun
  4. Cannot be determined with information given

22.  If the surface temperature of a star is doubled, but its radius remains the same, its new luminosity is ______its old luminosity.

  1. 16 times smaller
  2. 4 times smaller
  3. the same as
  4. 4 times larger than
  5. 16 times larger than

23.  The Stefan-Boltzmann Law applies to

  1. Individual atomic spectral lines
  2. A star’s chromosphere
  3. A star’s photosphere
  4. Clouds of interstellar gas
  5. Black-bodies
  6. All of the above
  7. c and e

24.  If a star’s luminosity increases, we can conclude that

  1. Its radius has increased
  2. Its temperature has increased
  3. Its temp or its radius has increased
  4. Its temp and its radius has increased
  5. None of the above

25.  A star that is very hot and not very luminous must have

  1. a very large radius
  2. a very small radius
  3. a very small mass
  4. a very great distance
  5. a very low velocity

26.  What part of the H-R diagram would you find a super giant star?

  1. Upper left
  2. Lower left
  3. Upper right
  4. Lower right
  5. Just above the sun on the main sequence

27.  Where do stars spend most of their time?

  1. On the main sequence
  2. In the super giant phase
  3. In the giant phase