19(a)] or from Ampere’s circuital law,
0
2
a
a
I
B
d
=µ
π
The conductor ‘b’ carrying a current Ib will experience a sideways
force due to the  field Ba The direction of this force is towards the
conductor ‘a’ (Verify this) We label this force as Fba, the force on a
segment L of ‘b’ due to ‘a’ The magnitude of this force is given by
Eq