A hypothetical magnetic field existing in a region is given by , where denotes the unit vector along the radial direction. A circular loop of radius a, carrying a current i, is placed with its plane parallel to the x-y plane and the centre at (0, 0, d). Find the magnitude of the magnetic force acting on the loop.


Given-
hypothetical magnetic field exists in a region,



Where


, is a unit vector along the radial direction a.


It is a circular loop of radius a


So, the length of the loop,


Electric current through loop = i



Also, the loop is placed with its plane parallel to the XY plane and its centre lies at (0,0, d).




The angle between the length of the loop l and the magnetic field B is θ


Magnetic force is given by



where,


B= magnetic field


I = current


l = length of the wire


and θ = the angle between B and l



Substituting the values -



Looking into the fig,




1