AP EAMCET2014PhysicsMagnetic Effects of Current
A steady current flows in a long wire. It is bent into a circular loop of one turn and the magnetic field at the centre of the coil is B . If the same wire is bent into a circular loop of n turns, the magnetic field at the centre of the coil is
Options
- AB n
- Bn B
- Cn B^2
- Dn^2 B
Correct answer
D. n^2 B
Step-by-step solution
The magnetic field a circular coil (for n number of loops) gathered B= ₀ n i 2 r n₁=1, n₂=2 2 r₁=n 2 r₂ gathered When, So aligned r₁ r₂ & = n 1 B₁ B₂ & = ₀ n₁ i / 2 r₁ ₀ n₂ i / 2 r₂ B B₂ & = n₁ n₂ r₁ r₂ B B₂ & = 1 n 1 n B₂ & =n^2 B aligned