Question
Two concentric coplanar semi-circular conductors form part of two current loops as shown in the figure. If their radii are 11 cm and 4 cm, calculate the magnetic induction at the centre.

Solution
Given, two concentric coplanar semi-circular conductors.
Radius of inner loop, r1 = 4 cm
Radius of outer loop, r2 = 11 cm
Current carried by the loops is 20 A and 40 A respectively.
Magnetic field due to circular loop at centre is given by,
Magnetic induction at centre due 4 qudadrant of wire is,
Radius of inner loop, r1 = 4 cm
Radius of outer loop, r2 = 11 cm
Current carried by the loops is 20 A and 40 A respectively.
Magnetic field due to circular loop at centre is given by,
Magnetic induction at centre due 4 qudadrant of wire is,