Question

Find magnetic field, energy stored , self inductance

2) Lons der an infitey tall Solcnoid Consing ot n sns fer unt ength, closely woynd on a very thin Rectang via Colomn with a with a and lensth b whee a> Thele is uotint Flowing though the wites in a Counter-cloekwise diection alound the Solenod a) Find the magntic teld nside and out Side the Solenos bl Find the eneigy Stoied in the magnene c) calulate the Sel-inductame Pet onit lenath o4 the Solenod d) Now add an infinitely long GylindCcol Won Co(c to the Soleno. as a Re(manent magnet with mgne t 2ation M and Cadius L, wheie Lb La. Find the gnctic telb everwhe fe inside the Solenoid

Answer 1

a)Magnetic field inside solenoid(B)=mu₀ni

Magnetic field outside solenoid=zero

b)Energy density(energy stored in magnetic field per unit volume)=B^2/2mu₀

B=mu₀ni

on substitution

(mu₀ni)^2/2mu_o

mu₀n^2i^2/2