PHYS4210 Quiz 2 - Electromagnetic Theory - Prof. James J. Napolitano, Quizzes of Physics

Download PHYS4210 Quiz 2 - Electromagnetic Theory - Prof. James J. Napolitano and more Quizzes Physics in PDF only on Docsity! Name: PHYS4210 Electromagnetic Theory Quiz 2 Feb 2009 This is a closed book quiz! Write the best choice in the space next to the question. 1. Five positive charges of magnitude q are arranged symmetrically around the cir- cumference of a circle of radius r. What is the magnitude of the electric field at the center of the circle? A. 0 B. q/r2 C. 5q/r2 D. q/r2 cos(2π/5) E. 5q/r2 cos(2π/5) 2. A positive charge Q is located at a distance L above an infinite grounded con- ducting plane: Unauthorized copying or reuse of any part of this page is illegal. GO ON TO THE NEXT PAGE. 8. A positive charge Q is located at a distance L above an infinite grounded conducting plane, as shown in the figure above. What is the total charge induced on the plane? (A) 2Q (B) Q (C) 0 (D) !Q (E) !2Q 9. Five positive charges of magnitude q are arranged symmetrically around the circumference of a circle of radius r. What is the magnitude of the electric field at the center of the circle? ( )k = 1 4 0!! (A) 0 (B) kq r2 (C) 5 2kq r (D) ( / ) cos /kq r2 2 5!! " (E) ( / ) cos /5 2 52kq r !! " 10. A 3-microfarad capacitor is connected in series with a 6-microfarad capacitor. When a 300-volt potential difference is applied across this com- bination, the total energy stored in the two capacitors is (A) 0.09 J (B) 0.18 J (C) 0.27 J (D) 0.41 J (E) 0.81 J 11. An object is located 40 centimeters from the first of two thin converging lenses of focal lengths 20 centimeters and 10 centimeters, respectively, as shown in the figure above. The lenses are separated by 30 centimeters. The final image formed by the two-lens system is located (A) 5.0 cm to the right of the second lens (B) 13.3 cm to the right of the second lens (C) infinitely far to the right of the second lens (D) 13.3 cm to the left of the second lens (E) 100 cm to the left of the second lens 12. A spherical, concave mirror is shown in the figure above. The focal point F and the location of the object O are indicated. At what point will the image be located? (A) I (B) II (C) III (D) IV (E) V 16 What is the total charge induced on the plane? A. 2Q B. Q C. 0 D. −Q E. −2Q 3. An infinitely long wire is charged by an amount λ per unit length. The electric field magnitude at a distance r from the wire is A. 0 B. λ/r C. λ/2πr D. λ/r2 E. λ/4πr2