Download Test 2, November 14, 2016 - Physics@Brock

Brock University
Number of pages: 9
Number of Students: 500
Number of hours: 50 min
Instructor: B.Mitrović
Test 2, November 2016
Course: ASTR 1P01
Date of Examination: November 14, 2014
Time of Examination: 17:00–17:50
1. The distance between the Moon and the Earth has been increasing over time. When the
distance was one third of its present value the force of gravity on the Moon exerted by
its present value.
the Earth was
(a) three times
(b) nine times
(c) one third of
(d) one ninth of
2. The force of gravity on the Earth exerted my the Moon is
on the Moon exerted by the Earth.
the force of gravity
(a) less than
(b) greater than
(c) equal to
3. The mass of a planet can be deduced from
third Kepler’s law as formulated by Newton.
of one of its satellites by using the
(a) the mass and the distance
(b) the orbital period and the distance
(c) the mass and the orbital period
4. According to Newton’s laws of motion, an object moving in a circle is subject to a force
pointing
(a) toward the center of the circle.
(b) away from the center of the circle.
(c) along its trajectory
(d) [There is no force on the object.]
5. Weighing the Earth experiment performed by Cavendish in 1798 determined the value
of
(a) the gravitational constant.
(b) the mass of the Earth.
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Course: ASTR1P01
Date: November 14, 2016
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6. The Earth’s atmosphere is not transparent to gamma-rays from outer space.
(a) True.
(b) False.
7. Which radiation has the longest wavelength?
(a) Radio waves.
(b) Red light.
(c) Blue light.
(d) gamma rays.
8. Which radiation has the shortest wavelength?
(a) Radio waves.
(b) Red light.
(c) Blue light.
(d) gamma rays.
9. Which photon carries the highest energy?
(a) Radio waves.
(b) Red light.
(c) Blue light.
(d) gamma rays.
10. Which photon carries the least amount of energy?
(a) Radio waves.
(b) Red light.
(c) Blue light.
(d) gamma rays.
11. The light gathering power of a 12-inch objective is
(a) four times
(b) sixteen times
(c)
(d)
1
4
1
16
2
that of 3-inch objective.
Course: ASTR1P01
Date: November 14, 2016
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12. Which of the following features determines the resolving power of a telescope?
(a) the focal length of the objective.
(b) the focal length of the eyepiece.
(c) the diameter of the objective.
(d) the diameter of the eyepiece.
13. If the focal length of the objective of a telescope is 120 cm and the focal length of the
eyepiece is 4 cm, the magnification is
(a) 3.
(b) 30.
(c) 300.
(d) 3000.
14. Of the three major powers of a telescope, magnification is the least important.
(a) True.
(b) False.
15. Concave mirrors focus all colors at the same point.
(a) True.
(b) False.
16. The resolving power of a telescope is a measure of its
(a) ability to resolve two stars as separate stars.
(b) magnification under good conditions.
(c) focal arrangement.
(d) [None of the above.]
17. Suppose that you have a reflecting telescope and a refracting telescope with the same
diameter objective. Which might use a Newtonian focal arrangement?
(a) The reflector.
(b) The refractor.
(c) Both.
(d) Neither.
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Course: ASTR1P01
Date: November 14, 2016
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18. One can increase the light-gathering power of a telescope by changing the eyepiece.
(a) True.
(b) False.
19. Increasing magnification makes the image brighter.
(a) True.
(b) False.
20. In large research telescopes the observation is often done in
focus.
(a) primary
(b) secondary
21. The main function of a telescope objective is to
(a) decrease chromatic aberration.
(b) collect light.
(c) disperse light.
(d) diffract light.
22. The best site for an optical telescope is a place where the air is
(a) thin and dry.
(b) thin and moist.
(c) thick and dry.
(d) thick and moist.
23. The parallax angle of the star Antares is 0.024 second of arc and the parallax angle of
Sirius is 0.38 second of arc. Which star is closer to us?
(a) Antares.
(b) Sirius.
24. A star is at a distance of 25 pc (parsec). Its parallax angle is
(a) 25 seconds of arc.
(b) 0.4 seconds of arc.
(c) 0.04 seconds of arc.
(d) 0.004 seconds of arc.
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Course: ASTR1P01
Date: November 14, 2016
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25. The parallax angle of a star is 0.25 seconds of arc. Its distance from the Sun in light-years
(ly) is about
(a) 0.25 ly.
(b) 6.6 ly.
(c) 13.2 ly.
(d) 4 ly.
26. If a star is 330 light years (ly) away, what is its approximate distance in parsecs (pc)?
(a) 10
(b) 100
(c) 1,000
(d) 10,000
27. If a star is 10 parsec (pc) away, what is its approximate distance in light years (ly)?
(a) 0.33
(b) 3.3
(c) 33
(d) 330
28. Two stars, S and U have the same luminosity (L) but the distance of S is ten times that
of U. The brightness of S is
that of U.
(a) 10 times.
(b) 100 times.
(c)
(d)
1
.
10
1
.
100
29. Two stars, S and U, appear equally bright and the distance of S is three times that of
U. The luminosity (L) of S is
that of U.
(a)
(b)
1
.
3
1
.
9
(c) 3 times.
(d) 9 times.
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Course: ASTR1P01
Date: November 14, 2016
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30. Star S is twice as luminous as star U, but its brightness is a half that of U. The distance
that of U.
of S is
(a) twice
(b) four times
(c) one half
(d) one quarter
31. A blue star has colder surface than a red star.
(a) True.
(b) False.
32. To determine the radius (R) of a star we need its
(a) luminosity and surface temperature.
(b) distance and luminosity.
(c) brightness and distance.
(d) brightness and luminosity.
33. Two stars U and W have the same radius, but the surface of U is twice as hot as that
of W. The luminosity of U is
that of W.
(a) twice
(b) four times
(c) eight times
(d) sixteen times
34. Which of these fundamental forces is the weakest?
(a) Gravitational.
(b) Electrical.
(c) Strong nuclear.
35. Which of these fundamental forces has the shortest range?
(a) Gravitational.
(b) Electrical.
(c) Strong nuclear.
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Course: ASTR1P01
Date: November 14, 2016
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36. When a star’s light passes through its cooler atmosphere
(a) it is redshifted.
(b) new spectral lines appear in the spectrum.
(c) it is blueshifted.
(d) photons of certain wavelengths are absorbed.
37. What is the most abundant chemical element in the main sequence stars?
(a) Oxygen (O).
(b) Carbon (C).
(c) Helium (He)
(d) Hydrogen (H).
38. The absorption lines of a main sequence star are thinner than the absorption lines of a
red giant star.
(a) True.
(b) False.
39. Which of these spectral classes contains the stars with the coolest surfaces?
(a) K.
(b) G.
(c) B.
(d) F.
40. To detect the spectroscopic binaries astronomers rely on
(a) the third Kepler’s law as formulated by Newton.
(b) the Wien’s law.
(c) the Doppler effect.
(d) the Stefan-Boltzmann law.
41. Which is more common?
(a) A star with a mass of 1 solar mass.
(b) A star with a mass of 100 solar mass.
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Course: ASTR1P01
Date: November 14, 2016
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For Questions 42-46 refer to Figure 1.
Figure 1
42. The main sequence star with the largest mass is
(a) S1 .
(b) S2 .
(c) S3 .
(d) S4 .
43. Among the main sequence stars, the one that is expected to live for the longest period
of time is
(a) S1 .
(b) S2 .
(c) S3 .
(d) S4 .
44. Star S1 has a larger radius than the star S6 .
(a) True.
(b) False.
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Course: ASTR1P01
Date: November 14, 2016
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45. Which one of these stars is a white dwarf?
(a) S1
(b) S7
46. Stars S4 and S6 have equal luminosity. Which star has the larger radius?
(a) S4
(b) S6
47. Which of these stars has the highest average density?
(a) A red giant star.
(b) A main sequence star.
(c) A white dwarf.
48. The star Betelgeuse is
(a) a red super-giant.
(b) a main sequence star.
(c) a white dwarf.
49. The spectral lines of a receding star are
(a) broadened.
(b) narrowed.
(c) blueshifted.
(d) redshifted.
50. Typical sizes of main sequence stars (in units of solar radius R⊙ ) are
(a) from 0.01 to 0.1 R⊙ .
(b) from 0.1 to 10 R⊙ .
(c) from 100 R⊙ to 1000 R⊙ .
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