Two wires A and B are of lengths 40 ~cm and 30 ~cm . A is bent into a circle of radius r and B into an arc of radius r . A current i₁ is passed through A and i₂ through B . To have the same magnetic inductions at the centre, the ratio of i₁: i₂ is

Step-by-step solution

For wire A , B₁= ₀ l ₁ 2 r where r= 40 2 For wire B , aligned Circumference & = length n r & =30 aligned or n = 30 r = 30 40 / 2 = 3 2 =n = 3 2 B₂= ₀ 4 ( i₂ r ) But B₁=B₂ array rlrl & or & ₀ i₁ 2 r & = ₀ 4 ( i₂ r ) or & i₁ i₂ & = 3 4 array