Well I have the answer already, just don't understand it. A rectangular coil of wire is hung from one arm of a balance, as my beautiful diagram will show. With the magnetic turned off, a Mass M is added to the pan on the other arm to balance the weight of the coil. When a constant magnetic field is turn on and there is a currentr of 8.50 A in the coil, how much additional mass m must be added to regain the balance? The magnetic field is also going into the page. Forgot to draw the X's. Image: http://img262.imageshack.us/img262/6318/balanaceyd8.th.jpg [Broken] Because of the magnetic field, the bottom length of the coil exerts a downward force but why is there a net force downwards, causing the torque? Shouldn't the upwards force from the magnetic field at the top of the rectangular coil cancel it out? Thanks in advance.