DAY 4 – DAW February

Magnetic shell, uniformly magnetized sphere; Ferromagnetic materials, hysteresis, energy loss. Biot-Savart law, Ampere’s law,


Q 1. State Biot-Savart law. Calculate the magnitude of axial magnetic induction due to a circular loop of area A carrying current I. [15 marks]

Q 2. A uniformly magnetised sphere of radius RR has magnetization M=M0z^\vec M=M_0\hat z. If the scalar magnetic potentials inside and outside the sphere are given as under

ϕm=Mo3Z;rR\phi_m=\frac{M_o}{3}Z;r\le R


ϕm=Mo3R3r2cosθ;r>R\phi_m=\frac{M_o}{3}\frac{R^3}{r^2}\cos \theta ;r> R

where r,θr, \theta  are two spherical coordinates, find the magnetic field inside and outside the sphere. [15 marks]

Video Solution at 11 pm