De La Salle University Manila Physics Fundamentals for Engineering 2 Quiz No. 3 Reviewer Multiple Choice: 1. Which of the two arrangements shown has the smaller equivalent resistance between points a and b? a. the series arrangement b. the parallel arrangement c. The equivalent resistance is the same for both arrangements d. The answer depends on the values of the individual resistances R 1, R 2, and R 3 e. Not enough information given 2. Three identical resistors, each of resistance R, are connected as shown. What is the equivalent resistance of this arrangement of three resistors? a. 3R b. 2R c. 3R/2 d. 2R/3 e. R/3 3. A 120-V, 60-W light bulb, a 120-V, 120-W light bulb, and a 120-V, 240-W light bulb are connected in parallel as shown. The voltage between points a and b is 120 V. Through which bulb is there the greatest voltage drop? a. the 120-V, 60-W light bulb b. the 120-V, 120-W light bulb c. the 120-V, 240-W light bulb d. All three light bulbs have the same voltage drop e. Not enough information given
4. Three identical light bulbs are connected to a source of emf as shown. Which bulb is brightest? a. light bulb A b. light bulb B c. light bulb C d. both light bulbs B and C (Both are equally bright and are brighter than light bulb A.) e. All bulbs are equally bright. 5. You wish to study a resistor in a circuit. To simultaneously measure the current in the resistor and the voltage across the resistor, you would place a. an ammeter in series and an voltmeter in series. b. an ammeter in series and an voltmeter in parallel. c. an ammeter in parallel and an voltmeter in series. d. an ammeter in parallel and an voltmeter in parallel. 6. A battery, a capacitor, and a resistor are connected in series. Which of the following affect(s) the maximum charge stored on the capacitor? a. the emf e of the battery b. the capacitance C of the capacitor c. the resistance R of the resistor d. both e and C e. all three of e, C, and R 7. A battery, a capacitor, and a resistor are connected in series. Which of the following affect(s) the rate at which the capacitor charges? a. the emf e of the battery b. the capacitance C of the capacitor c. the resistance R of the resistor d. both C and R e. all three of e, C, and R
8. When a charged particle moves through a magnetic field, the direction of the magnetic force on the particle at a certain point is a. in the direction of the magnetic field at that point. b. opposite to the direction of the magnetic field at that point. c. perpendicular to the magnetic field at that point. d. none of the above e. The answer depends on the sign of the particle s electric charge. 9. A particle with a positive charge moves in the xz-plane as shown. The magnetic field is in the positive z-direction. The magnetic force on the particle is in a. the positive x-direction. b. the negative x-direction. c. the positive y-direction. d. the negative y-direction. e. none of these 10. A positively charged particle moves in the positive z-direction. The magnetic force on the particle is in the positive y-direction. What can you conclude about the x-component of the magnetic field at the particle s position? a. B x > 0 b. B x = 0 c. B x < 0 d. either A or C 11. A positively charged particle moves in the positive z-direction. The magnetic force on the particle is in the positive y-direction. What can you conclude about the y-component of the magnetic field at the particle s position? a. B y > 0 b. B y = 0 c. B y < 0 d. either A or C
12. A positively charged particle moves in the positive z-direction. The magnetic force on the particle is in the positive y-direction. What can you conclude about the z-component of the magnetic field at the particle s position? a. B z > 0 b. B z = 0 c. B z < 0 d. Either A or C 13. Under what circumstances is the total magnetic flux through a closed surface positive? a. if the surface encloses the north pole of a magnet, but not the south pole b. if the surface encloses the south pole of a magnet, but not the north pole c. if the surface encloses both the north and south poles of a magnet d. none of the above e. all of the above 14. When a charged particle moves through a magnetic field, the trajectory of the particle at a given point is a. parallel to the magnetic field line that passes through that point. b. perpendicular to the magnetic field line that passes through that point. c. neither parallel nor perpendicular to the magnetic field line that passes through that point. d. any of the above, depending on circumstances e. none of the above 15. A charged particle moves through a region of space that has both a uniform electric field and a uniform magnetic field. In order for the particle to move through this region at a constant velocity, a. the electric and magnetic fields must point in the same direction. b. the electric and magnetic fields must point in opposite directions. c. the electric and magnetic fields must point in perpendicular directions. d. the answer depends on the sign of the particle s electric charge. e. none of the above
16. A circular loop of wire carries a constant current. If the loop is placed in a region of uniform magnetic field, the net magnetic force on the loop is a. perpendicular to the plane of the loop, in a direction given by a right-hand rule. b. perpendicular to the plane of the loop, in a direction given by a left-hand rule. c. in the same plane as the loop. d. zero. e. The answer depends on the magnitude and direction of the current and on the magnitude and direction of the magnetic field. 17. A circular loop of wire carries a constant current. If the loop is placed in a region of uniform magnetic field, the net magnetic torque on the loop a. tends to orient the loop so that its plane is perpendicular to the direction of the magnetic field. b. tends to orient the loop so that its plane is edge-on to the direction of the magnetic field. c. tends to make the loop rotate around its axis. d. is zero. e. The answer depends on the magnitude and direction of the current and on the magnitude and direction of the magnetic field. 18. An airplane made of some light metal navigates at constant speed eastward following the Arctic Circle where the earth s magnetic field has a considerable downward component. Assume that the wings are maintained level with the surface of the earth. Which of the following is true? a. The electrons in the metal wings will experience no magnetic force at all. b. The wing tip closer to geographic North will accumulate a negative charge while the other will accumulate positive charge of the same magnitude. c. The wing tip closer to geographic North will accumulate a positive charge while the other will accumulate negative charge of the same magnitude. d. The front of the plane will accumulate a positive charge while the tail end will accumulate a negative charge of the same magnitude. e. The front of the plane will accumulate a negative charge while the tail end will accumulate a positive charge of the same magnitude.
19. The charged particle moving in the plane of the page follows a clockwise spiral of decreasing radius in the uniform magnetic field B directed into the page. A reasonable explanation is: a. The charge is negative and it is gaining kinetic energy b. The charge is positive and speeding up c. The charge is negative and speeding up d. The charge is negative and the magnetic field is increasing e. None of the above 20. The magnetic moment of the solenoid shown is: a. directed upwards (along the axis of the cylinder) b. directed downwards (along the axis of the cylinder) c. directed to the left of the page d. directed to the right of the page e. in no direction since B = 0
Answer Key: 1. B 2. C 3. D 4. A 5. B 6. D 7. D 8. C 9. D 10. C 11. B 12. E 13. D 14. D 15. C 16. D 17. A 18. C 19. D 20. B Prepared by: John Carlo R. Samarita