SOME MAGNETIC FIELDS 



,,, . . ., , _ . ,. , , . Msin0 

 Ihe intensity due to rG is perpendicular to / and is 



The resultant is ^-/y/4 cos 2 + sin 2 0. 



The direction makes an angle </> with CP given by 



'sin 1 



tan = ^ ^ = r, tan 0. 



2 cos 2 



FIG. 100. 



FIG. 167. 



The following construction gives the direction of the intensity. 

 Draw PN, Fig. 108, perpendicular to CP, meeting the axis produced 



FIG. 168. 



in N: complete the rectangle CPNQ. Bisect CQ in T. Then 

 TP is the direction of the intensity at P. For 



