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Physics 002 Final Examination 24 May, 2003
Time allowed: 180 minutes Total: 140 marks
Name:
Student ID:
Seat:
A
Section
Marks
A
B
C
D1
D2
D3
D4
Total
Table 1: Useful Data
1 parsec
3.26 light years
1 parsec
206,265 AU
1 Astronomical Unit
1.50 1011 m
Speed of light
3 108 m/s
Universal gravitational constant
6.67 10-11 N.m2/kg2
Mass of Sun MSun
1.99 1030 kg
1 solar radius
6.9599 108 m
Figure 1: HR Diagram with Luminosity Classes
Section A: Multiple Choice (20 marks)
(1) What event(s) lead(s) to the formation of a red giant star?
A. a contracting core of helium
B. hydrogen shell burning
C. expanding outer layers
D. all of the above
E. none of the above
Ans. ______
(2) An iron core cannot support a star because
A. Iron has poor nuclear binding energy.
B. Iron cannot undergo nuclear fusion to produce energy.
C. Iron supplies too much pressure.
D. Iron is in the form of a gas, not a solid, in the center of a star.
E. Iron will ignite itself in the core like phosphors in the air.
Ans. ______
(3) If a planetary nebula emitted 3 emission lines (blue, yellow, red) of equal intensity, and we viewed this planetary nebula after the light passes through dusty interstellar gas, then how would the observed spectrum appear?
A. unchanged; all would have the same intensities
B. blue would be brightest, followed by yellow, then red
C. red would be brightest, followed by yellow, then blue
D. yellow would be brightest, followed by red, then blue
E. The three colors combined to show a white line spectrum.
Ans. ______
(4) Which of the following best describes a nova?
A. An explosion which creates a planetary nebula and a white dwarf.
B. The explosive burning of hydrogen on the surface of a white dwarf in a binary system.
C. The carbon detonation of a white dwarf when its mass exceeds 1.4 solar masses in a binary star system.
D. The collapse and bounce of an iron core in an isolated massive star.
E. The X-ray burst produced by a neutron star binary system.
Ans. ______
(5) You observe a 10 solar mass star in a binary system with a companion that does not give off enough light to be seen. However, you do know that the binary's period is 20 years, and the semimajor axis is 20 AU. What is the companion object?
Name:
Student ID:
A
(5) (continued)
A. it can't be determined from this information
B. a brown dwarf
C. a white dwarf
D. a neutron star
E. a black hole Ans. ______
Section B: Short Questions. Give your numerical answers to 2 significant figures. (16 marks)
Rigel is a star classified as B8Ia. Its apparent visual magnitude is 0.18.
(1) Wh