Question

For example, consider the situation shown on the right in which a rectangular loop is 8 inside a region of space with a magnetic field that points into the page. The magnetic field also increases. A. Borig: What is the direction of the original magnetic field? Into the page B. PB: Is ºb decreasing, increasing or staying the same? Increases because the magnitude of the magnetic field increases C. Bind: What is the direction of the induced magnetic field? Since OB is increasing, the induced magnetic field is trying to reduce the flux, and it does that by opposing the original magnetic field. So the induced magnetic field points out of the page D. lind: What is the direction of the induced current in the loop that causes the induced magnetic field? Using the second right hand rule, we determine that the induced current must be counterclockwise. Since there is a counterclockwise induced current in the loop, and the loop is in an external magnetic field that points into the page, there will be a magnetic force on each side of the loop. We can figure out the direction by using the first right hand rule: Left side: Iind is down, Borig is into the page -> FB points right; Top side: lind is left, Borig is into the page -> FB points down Right side: lind is up, Borig is into the page -> FB points left; Bottom side: lind is left, Borig is into the page -> FB points up In other words, all the forces point inwards because nature doesn't like the fact that the flux is increasing and tries to reduce it by creating forces that try to decrease the area of the loop. Now, suppose that instead, the magnetic field is pointing out of the page and decreasing. Follow the steps to figure out the direction of the induced current in the loop, and once you have that, figure out the direction of the magnetic force on each side of the loop. Remember that this force is caused by the original magnetic field and the induced current. A. Borig: B. "B: Force on left side: Force on top side: Force on right side: Force on bottom side: C. Bind: D. lind:

Answer 1

Now, suppose that instead, the magnetic field is pointing out of the page and decreasing. Follow the steps to figure out the direction of the induced current in the loop, and once you have that, figure out the direction of the magnetic force on each side of the loop. Remember that this force is caused by the original magnetic field and the induced current. A. B.: out of page B. OB: decreasing Force on left side: left Force on top side: up Force on right side: right Force on bottom side: down C. Bind: out of page D. lind: countercloc