I. A resistor R, an inductor L, and a source of emf & are connected in series with a switch that is initially open. Which of the following describes the current I in the circuit as a function of time after the switch is closed? A f(1-ez) B is directed B is directed into the page into the page Figure 1 @ * (1te " ) Figure 2 * (1 -e-") Four conducting rods are connected to form the flexible diamond-shaped assembly shown in Figure 1. The assembly is placed in a uniform magnetic field that is directed into the plane of the page. The top and bottom vertices of the assembly are slowly pulled apart until the assembly is in the diamond shape shown in Figure : During this process, which of the following statements about the induced current in the assembly is correct? D A The induced curren E fet B The induced curre wise throughout the process. C The induced current is directed ughout the process. D The induced current is directed clockwise, then counterclockwise. E The induced current is directed counterclockwise, then clockwise. R 2 X In the circuit shown, E = 12.0 V, L = 1.00 H, R, is 2.00 02, R2 is 3.00$2, and Ry is 4.00 $2. The switch is initially open. What is the current as a function of time X X X after the switch is closed at time t = 0? X X X A I (t) = 2.31e-5.20t A B X X B I (t) = 5.20e-/2.22 A A square loop of wire moves at constant velocity into a region containing a uniform magnetic field directed into the page, as shown. As the loop of wire enters the field, its speed changes. Which of the following correctly predicts the change in speed and best explains why it changes? C I (t) = 2.31 (1 - e-5.20t) A A The amount of wire in the field is increasing. This produces an increasing current, which according to Lenz's law causes the loop to slow down. D I (t) = 2.31 (1 - e-*/5.20) A B The amount of wire in the field is increasing. This provides more resistance, which causes the induced current to decrease, which according to Lenz's law causes the loop to speed up. E) I (t) = 5.20 (1 - e-2.22t) A C The magnetic flux through the loop is increasing. According to Faraday's law, th an electric field, which produces an electric force on the loop that causes the loop to speed up 12 V 69 D The magnetic flux through the loop is increasing. According to Faraday's law, this induces an electric field, which produces current in a direction predicted by Lenz's law. The wire within the field experiences a net magnetic force that slows the loop down. A (E The magnetic flux through the loop is increasing. According to Faraday's law, this induces an electric field, which produces current in a direction 2.OH predicted by Lenz's law. The wire within the field experiences a net magnetic force that speeds the loop up. Question 11 e. A switch is used in the circuit and is initially open. The switch is then closed. Which of the following gives the readings on the amme ely after the switch is closed, and a long time after the switch is closed? A Immediately after the switch is closed A long time after the switch is closed 1.0 A B Immediately after the switch is closed A long time after the switch is closed OA 2.0 A Immediately after the switch is closed A long time after the switch is closed 1.0 A 2.0 A Immediately after the switch is closed A long time after the switch is closed 2.0 A 1.0 A Immediately after the switch is closed A long time after the switch is closed 1.6 A 1.6 A