- #1
JosephK
- 40
- 2
Homework Statement
Figure is attached.
A thin copper bar of length = 14.0 cm is supported horizontally by two (nonmagnetic) contacts. The bar carries current I1 = 105 A in the -x direction, as shown in the figure below. At a distance h = 0.500 cm below one end of the bar, a long straight wire carries a current I2 = 200 A in the z direction. Determine the magnitude and direction of the magnetic force exerted on the bar.
Homework Equations
I = μI/2∏r
F = IL X B
The Attempt at a Solution
By the Biot-Savart Law, a magnetic field is created by a current carrying wire. Because the wire carries a current I, there is a magnetic field in the region. Since the wire is long, we may assume infinite length. The magnetic field of an infinite wire length r away we calculated B = μI/2∏r.
From the classroom demonstration we learned a current carrying wire in a magnetic field experiences a magnetic force. The magnetic force is perpendicular to both current element ds and B. The force experienced by the rod is F = ILXB. Since B varies over the length of the bar, we need to integrate. Also, the appropriate equation to use is dF = I dsXB since the angle between ds and B vary as well. After combining the equation for B and replacing theta in terms of r and integrating should I have the answer?