A long solenoid produces a uniform magnetic flux density when its interior is empty…
PHYSICS · Multi-part · CBSE · Physics · Magnetism and Matter · Magnetism and Matter
Problem
A long solenoid produces a uniform magnetic flux density B0 when its interior is empty (air core). When a solid cylindrical sample of an unknown material is inserted so that it completely fills the interior, the flux density measured at the center of the solenoid increases to B=2.4×102B0.
Assume the current in the solenoid is unchanged, and that the magnetic field intensity H remains the same before and after insertion.
(a) Determine the relative permeability μr of the unknown material.
(b) The inductance of the empty solenoid is L0. Calculate the new inductance L after the sample is inserted, expressing L in terms of L0.
(c) After insertion of the sample, the current in the solenoid is reduced to one‐tenth of its original value. Express the resulting magnetic flux density Bnew in terms of B0.