Brock University Test 1, May 2014 Number of pages: 9 Course: ASTR 1P01 Number of Students: 500 Date of Examination: May 21, 2014 Number of hours: 50 min Time of Examination: 14:00 14:50 Instructor: B.Mitrović 1. During May the constellation Cancer is visible near the Western Horizon. However in June the Cancer is no longer visible in the night sky. The reason for that is that (a) the Earth is spinning about North-South axis. (b) the Earth is revolving around the Sun. (c) the Earth has rotational axis tipped by 23.5 relative to the vertical to the ecliptic. (d) [None of the above.] 2. Vega is the brightest star in the constellation Lyra and the second brightest star in the northern hemisphere. Its distance from us is 25 light-years (ly). How long does it take light emitted by Vega to travel this distance? (a) 25 hours. (b) 25 days. (c) 25 months. (d) 25 years. 3. The average distance between the Earth and the Sun is about (a) 1.5 million km. (b) 15 million km. (c) 150 million km. (d) 1.5 billion km. 4. The angular displacement of stars resulting from their annual motion, i.e. because of the Earth s revolution around the Sun, is about (a) 1 per second. (b) 1 per minute. (c) 1 per hour. (d) 1 per day. 5. If theearthwas rotating (spinning) fromeast to West asobserved fromabove thenorth Pole, the stars and the Sun would rise in the West and set in the East. 1
Course: ASTR1P01 Date: May 21, 2014 page 2 of 9 pages 6. Pluto is no longer considered to be a planet because (a) it does not orbit the Sun. (b) it does not have enough mass to assume approximately spherical shape under its own gravity. (c) it has not cleared its orbit that is, it is not the only body of its size in the region of the Solar System at that distance from the Sun. 7. The Andromeda Galaxy 2.5 million light years away is the most distant object easily seen by the unaided eye. How long does it take light produced by its stars to reach the Earth. (a) 2.5 years. (b) 2,500 years. (c) 2.5 million years. (d) 25 million years. 8. Over time the Moon is (a) slowly approaching the Earth. (b) slowly drifting away from the Earth. (c) at a constant distance from the Earth. 9. The Milky Way belongs to a cluster of galaxies called (a) Milky Way cluster. (b) Global group. (c) Local group. (d) Lactic cluster. 10. In their daily motions the Sun and the stars appear to be moving parallel to celestial equator because (a) the Earth is revolving around the Sun. (b) the Earth is rotating (spinning) from West to East. (c) the Earth s rotational axis is perpendicular to the equatorial plane. (d) [The statement is wrong. In their daily motions the Sun and the stars appear to be moving parallel to the ecliptic] 2
Course: ASTR1P01 Date: May 21, 2014 page 3 of 9 pages 11. Suppose that you are not very familiar with the stars and constellations, but you notice that the circumpolar stars which you observe move counterclockwise. Then you must be located in the (a) northern hemisphere. (b) southern hemisphere. (c) [No definite statement can be made.] 12. How can one locate the north celestial pole at the present time? (a) By locating the star which is at the end of the handle of the Big Dipper. (b) By locating the star which is at the end of the handle of the Little Dipper. (c) By locating the star in the middle of Cassiopeia. (d) By locating the star in the middle of Cygnus (Northern Cross). 13. For an observer on the equator (a) all stars are circumpolar stars. (b) about 50% of stars are circumpolar and the rest of the stars rise and set. (c) no star is a circumpolar star. (d) [No statement can be made without knowing the longitude of the observer.] 14. If a star rises tonight at 10:15 pm, yesterday it rose at about (a) 10:15 pm. (b) 10:19 pm. (c) 10:11 pm. 15. The stars in the Big Dipper are all at the same distance from us. 16. If your celestial horizon coincides with the celestial equator you are located (a) on the equator. (b) at either the North Pole or the South Pole. (c) [No statement can be made.] 3
Course: ASTR1P01 Date: May 21, 2014 page 4 of 9 pages 17. If a celestial pole is on your horizon you are located (a) on the equator. (b) at either the North Pole or the South Pole. (c) [No statement can be made.] 18. On Vernal equinox the Sun is (a) above celestial equator. (b) below celestial equator. (c) on celestial equator. 19. As seen from Ontario in May the Sun (a) rises north of east and sets south of west. (b) rises south of east and sets north of west. (c) rises south of east and sets south of west. (d) rises north of east and sets north of west. 20. As seen from Ontario on summer solstice the Sun is (a) above celestial equator. (b) below celestial equator. (c) on celestial equator. 21. On the day of winter solstice the number of hours of darkness at the latitude 80 North is (a) 0. (b) 12. (c) 24. 22. As seen from Ontario on winter solstice the Sun is (a) above celestial equator. (b) below celestial equator. (c) on celestial equator. 23. 3,000 years ago the star closest to the north celestial pole was Polaris. 4
Course: ASTR1P01 Date: May 21, 2014 page 5 of 9 pages 24. What is the angular displacement of a star in the night sky after 6 hours? (a) 6. (b) 15. (c) 60. (d) 90. For Questions 25-31 refer to Figure 1. Figure 1 25. When you are at b) it is (a) sunrise. (b) noon. (c) sunset. (d) midnight. 26. You can observe the waning crescent Moon at sunset. 27. You can observe the waxing gibbous moon at midnight. 5
Course: ASTR1P01 Date: May 21, 2014 page 6 of 9 pages 28. The third-quarter Moon sets at (a) sunrise. (b) noon. (c) sunset. (d) midnight. 29. The first-quarter Moon rises at (a) sunrise. (b) noon. (c) sunset. (d) midnight. 30. You can observe the full moon in the evening. 31. When the Moon is at 6) it is waxing gibbous. 32. If the Moon s orbit was in the plane of the ecliptic, i.e. in the plane of the Earth s orbit around the Sun, (a) we would observe eclipses as often as we do now. (b) we would observe the solar and the lunar eclipse once a month. (c) we would never observe eclipses. (d) we would observe eclipses occasionally, but less often than now. 33. The precession of the Moon s orbit, and the resulting precession of the line of nodes, (a) has no effect on the dates of the eclipses from year to year. (b) causes the dates of the eclipses to shift by 20 days from year to year. (c) causes the dates of the vernal equinox to shift by 20 days from year to year. (d) [The statement is wrong. The Moon s orbit does not precess.] 6
Course: ASTR1P01 Date: May 21, 2014 page 7 of 9 pages 34. The pase of the Moon when a solar eclipse is observed is (a) new moon. (b) full moon. 35. The pase of the Moon when a lunar eclipse is observed is (a) new moon. (b) full moon. 36. How did Aristarchus deduce that the Sun is at a much greater distance than the Moon? (a) From the length of the shadow of an obelisk. (b) By comparing the intervals of time between two quarter phases of the Moon. (c) From the difference in their angular sizes. (d) From Moon s elevation above the ecliptic. 37. Galileo s observation of the gibbous and the quarter phases of Venus supported (a) the geocentric model. (b) the heliocentric model. 38. At the time of Copernicus, the fact that parallax shift of the brighter stars could NOT be seen was considered evidence for which model? (a) The geocentric model. (b) The heliocentric model. 39. According to Kepler s second law, a planet moves fastest when it is (a) closest to the Sun. (b) at the greatest distance from the Sun. (c) [The speed of the planet does not depend on its distance from the Sun.] 40. The Copernican model explained retrograde motion of planets as a result of (a) their motion along epicycles. (b) difference in speeds of the Earth and another planet in their orbits around the Sun. (c) planets stopping their eastward motion, moving westward awhile, and then resuming their eastward motion. (d) [None of the above.] 7
Course: ASTR1P01 Date: May 21, 2014 page 8 of 9 pages 41. If the distance between two bodies is decreased by a factor of 3 (three), the force of gravity which they exert on each other is (a) increased by a factor of 3 (three). (b) reduced by a factor of 3 (three). (c) increased by a factor of 9 (nine). (d) reduced by a factor of 9 (nine). 42. It is possible to determine the mass of a planet from the orbital data (the period and the orbital radius) of one of its satellites. 43. Which radiation has the shortest wavelength? (a) Infrared. (b) Red light. (c) Blue light. (d) X-ray. 44. The Earth s atmosphere is transparent to X-rays from outer space. 45. Which of the following features determines the light gathering power of a telescope? (a) the diameter of the objective. (b) the diameter of the eyepiece. (c) the focal length of the objective. (d) the focal length of the eyepiece. 46. Lenses focus all colours at the same point. 8
Course: ASTR1P01 Date: May 21, 2014 page 9 of 9 pages 47. A telescope which has a hole in the middle of the primary mirror to allow light reflected from its secondary mirror to reach a focus behind the primary mirror is said to have focal arrangement. (a) Newtonian. (b) Cassegrain. (c) Galilean. (d) Copernican. 48. If a star is 50 parsec (pc) away, what is its approximate distance in light years (ly)? (a) 1.6 (b) 16 (c) 160 (d) 1,600 49. Two stars, S and U have the same luminosity (L) but the distance of S is five times that of U. The brightness of S is that of U. (a) 1 5. (b) 1 25. (c) 5 times. (d) 25 times. 50. Star S radiates most energy at 400 nanometers and star U radiates most energy at 700 nanometers. From this we can conclude that (a) star S has hotter surface than star U. (b) star S has colder surface than star U. (c) both stars have the same surface temperature. (d) [No comparison of their surface temperatures can be made.] 9