Exam Name___________________________________ MULTIPLE CHOICE. - PDF document

Exam Name___________________________________ MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) A double � concave lens has equal radii of curvature of 15.1 cm. An object placed 14.2 cm from 1) the lens forms a virtual image 4.60 cm from the lens. What is the index of refraction of the lens material? A) 2.11 B) 1.96 C) 2.03 D) 2.19 2) An astronomical telescope is made from two lenses: the objective lens has a focal length of 2) f � 343 cm, and the eyepiece lens has a focal length of f � 9.0 cm. (a) What is the total length of the telescope? (b) What is the angular magnification of the telescope? (c) What is the magnification if the telescope is viewed by looking through the objective lens first? A) (a) 352 cm B) (a) 668 cm C) (a) 704 cm D) (a) 334 cm (b) 38.11 (b) 1.03 (b) 0.97 (b) 0.03 (c) 0.03 (c) 0.97 (c) 1.03 (c) 38.11 3) Astronomers are proud of their telescopes, and often say they can "resolve a dime at so many 3) miles." How many miles can you move a disk ( D � 6.0 cm) from a 325 � cm � diameter telescope mirror and just resolve it using light of wavelength 785 nm? A) 31 mi B) 610,000,000 mi C) 61 mi D) 130 mi 4) An X � ray photon that has a wavelength of 8.1 nm. What is its energy? 4) A) 2.5 x 10 � 17 J B) 8.2 x 10 � 26 J C) 2.5 x 10 � 26 J D) 8.2 x 10 � 21 J 5) Gamma rays are photons with very high energy. What is the wavelength of a gamma � ray 5) photon with energy 3.4 � 10 � 13 J? A) 8.8 x 10 � 13 m B) 7.0 x 10 � 13 m C) 5.9 x 10 � 13 m D) 7.9 x 10 � 13 m 6) What is the velocity of an electron with a de Broglie wavelength of 3.13 μm? 6) A) 233 m/s B) 291 m/s C) 200 m/s D) 170 m/s 7) You want to confine an electron and you want to know for certain that the electron's speed is 7) no more than 87 m/s. What is the length of the smallest box in which you can do this? A) 8.4 x 10 � 6 m B) 1.0 x 10 � 6 m C) 4.2 x 10 � 6 m D) 2.1 x 10 � 6 m 8) Three charges of magnitude 9.0 x 10 � 4 C each are located at x � 1.0 m, y � 0.0 m, at x � 0.0 m, 8) y � 0.0 m, and at x � � 1.0 m, y � 0.0 m. The one in the middle is negative, while the other two are positive. What is the net Coulombic force exerted by them on a negative 9.0 x 10 � 5 C charge located at x � 0.0 m, y � 2.0 m? (The value of k is 9.0 x 109 N � m2/C2.) A) 1100 N attractive B) 790 N repulsive C) 1100 N repulsive D) 790 N attractive 1

9) In the figure below d � 7.2 cm. What is the electric field at the position indicated by the dot in 9) the figure? A) 1.0 x 104 N/C, at 5.2° below the horizontal B) 1.1 x 104 N/C, at 5.2° below the horizontal C) 1.1 x 104 N/C, at 8.5° below the horizontal D) 1.0 x 104 N/C, at 8.5° below the horizontal 10) The figure shows a thin rod of length L � 5.0 cm with total charge Q � 9.5 nC. What is the 10) magnitude of the electric field E at x � 3.0 cm? A) 3.1 x 105 N/C B) 4.2 x 105 N/C D) 9.5 x 104 N/C C) 2.0 x 105 N/C 2

Answer Key Testname: PHYSICS2212_REVIEW2 1) A 2) A 3) C 4) A 5) C 6) A 7) C 8) D 9) A 10) A 3