Consider two thin identical conducting wires covered with very thin insulating material. One of the wires is bent into a loop and produces magnetic field B ₁ , at its centre when a current I passes through it. The ratio B ₁: B ₂ is:

Step-by-step solution

For loop B= ₀ nI 2 a where, a is the radius of loop. Then, B₁= ₀ I 2 a Now, for coil B = ₀ I 4 2 nA x ^3 at the centre x= radius of loop aligned B ₂ &= ₀ 4 2 3 ( I / 3) ( a / 3)^2 ( a / 3)^3 &= ₀ 3 I 2 a & B ₁ ~B ₂ = ₀ I / 2 a ₀ 3 I / 2 a B ₁: B ₂=1: 3 aligned