In the figure, a compass sits 1.0 cm above a wire in a circuit containing a 1.0 F capacitor charged to 50 V , a 2.0Ω resistor, and an open switch. Initially, the compass is lined up with the earth's magnetic field. The switch is then closed, so there is a current in the circuit, and the switch remains closed until the capacitor has completely discharged.
a. At the position of the compass, what is the direction of the magnetic field due to the current in the wire after the switch is closed? (Assume that the compass is only affected by the field created by the current in the wire that is directly below it.)
b. At the position of the compass, what is the magnitude of the magnetic field due to the current in the wire at the following times after the switch is closed? (Fill in the table to help with your calculations. The switch is closed at t = 0 s.) How does this compare with the magnitude of the field of the earth? Use 50 -T for the magnitude of the earth's field.
c. Describe how the compass orientation changes right after the switch is closed, and how the compass orientation changes as time goes on.
