Book: Matter and Interaction 4th edition by Chabay and Sherwood question from ch
ID: 1633904 • Letter: B
Question
Book: Matter and Interaction 4th edition by Chabay and Sherwood question from chapter 17.
Deflecting a compass needle When you bring a current carrying wire down onto the top of a compass, aligned with the original direction of the needle and 5 mm above the needle, the needle deflects by theta = 11 degree (see the figure). (a) Which of the following statements are correct? Select all that apply. The magnetic field under the wire, due to the current, points North. The magnetic field under the wire, due to the current, points to the East. Conventional current in the wire is flowing downward (South). Conventional current in the wire flows upward (North). The magnetic field under the wire, due to the current, points to the West. Electron current in the wire is flowing upward (North). (b) Calculate the amount of conventional current flowing in the ire. The measurement was made at a locat on where the horizontal component of e Earth's magnetic field is B_Earth = 2 times 10^-5 tesla.Explanation / Answer
a) second third and sixth statements are correct. Field is eastwards, conventional current points south, electron current points north.
b) B = uo i / 2 pi r
2e-5*tan 11 degree = i* 2e-7/0.005
i = 2e-5*tan 11 degree*0.005/2e-7
= 0.0972 A. answer