MHT CET202211 Aug 2022Morning ShiftPhysicsMagnetic Effects of CurrentActual
A long wire carries a steady current. It is bent into a coil of one turn such that magnetic induction at centre is B , then same wire is bent to from a coil of smaller radius of n turns such that magnetic induction at centre is B , then
Options
- AB^ =B / n^2
- BB^ =n B
- CB^ =B
- DB^ =n^2 B
Correct answer
D. B^ =n^2 B
Step-by-step solution
Initially, B= ₀ I 2 r For coil with smaller radius r^ = r n , such that 2 r=n (2 r^ ) : aligned & B^ =n ( ₀ I 2 r^ )= ₀ n I 2(r / n) & B^ =n^2 B aligned