Three identical constant pitch thin helical coils (having a pitch 3mm, axial length 450mm and inner diameter 20mm) are positioned along a common axis. The axial distance between the first and the second is 55mm, the distance between the second and the third is 100mm and the distance between the first and the third is 605mm a) Calculate the mutual inductance between all pairs of coils i.e., M1,2 and M1,3 b) Calculate the total effective inductance of a system made from the three coils connected in series, if all coils are generating magnetic fields in the same direction.