I'm looking at this picture from part of an explanation of the torque on a coil of current arranged as a solenoid: http://www.physics.sjsu.edu/becker/physics51/images/28_30_Torgue_on_solenoid.jpg Now, they claim that the torque is directed into the page, but I can't understand why. I agree that the torque of an individual current loop about its center would be into the page, but if we're trying to find the torque about the center of the entire solenoid, I seem to think that the total torques should cancel out. Here's my reasoning. The force on the left side of the wires will point up, and the force on the right side points down, in accordance with the right hand rule. Now, getting the torque on, say, the top left corner, we find that it points out of the page due to τ= r x F and by the same equation, the torque due to the top right corner of the solenoid points into the page. This would happen for each loop in the solenoid, so shouldn't the torques cancel? Why can we treat the entire solenoid as a single current loop, and multiply by the of turns in it?