1. when there is a current in a loop and it is placed in a magnetic field then there will be the torque on it along the direction of mxB axis.but that axis will pass through which point.will that torque act through the center of the loop only?? 2. suppose a current (I) carrying loop (of R)is rolled on a sphere(only single turn) along diameter and sphere is kept on an inclined plane of inclination theta where plane of loop is parallel to inclined plane .there is a magnetic field in downwards direction.we have to find the value of B for which sphere is in rotational equilibrium (gravity is there). I guess the magnetic torque will act through the centre of the loop .But here they have balanced the net torque about the "point of contact" of sphere and the inclined plane and not about the centre of the loop.(it means magnetic torque was acting about the point of contact.)WHY?