The correct option (b) [(π/2) + 1]a2 I k
Explanation:
A1 = area of central square = (side)2 = a2
A2 = area of all focus semicircles = 4 × (πr2/2) = 2πr2
Here radius = (a/2)
Hence A2 = 2π(a/2)2 = 2π × (a2/4) = (πa2/2)
∴ Total area = A1 + A2 = a2 + (π/2)a2 = a2[1 + (π/2)]
Magnetic moment = M = IA = Ia2[1 + (π/2)]k