AP EAMCET20224 Jul 2022Evening ShiftPhysicsMagnetic Effects of CurrentActual
A steel wire of length l and magnetic moment M is bent into a semicircular arc of radius R . The new magnetic moment is
Options
- AM
- B2 R M π l
- C2 M π
- D2 π R M l
Correct answer
C. 2 M π
Step-by-step solution
When wire is bent in the form of semicircular arc then, l = π r ∴ The radius of semicircular arc, r = l π Distance between two end points of semicircular wire = 2 r = 2 l π ∴ Magnetic moment of semicircular wire = m × 2 r = m × 2 l π = 2 π m l But m l is the magnetic moment of straight wire i.e., m l = M ∴ New magnetic moment = 2 π M