Question

Winter 2005 Q.8 (a) Derive an expression for self inductance per unit length of a parallel wire of radius a separated by a distance D, where one wire is a return circuit for the current in the other. (b) Using Maxwell's curl equations derive the wave equation in H for a plane wave travelling in the positive x direction in a medium with constants u = Ho E = €, and o = 0. The electric field is in the y direction. (10) (10)

Answer 1

Solution: (a) tic field at a distance x = lo lt llo I zax 25 (d-) - Lo I slui Zá a dal magh an elebes) i 4 polo re]ore of width da Flux through an elementary area and length writy = B. Area = B (dx-1): - Mo esteschaned with the de O d-a 27 1 d-xl

4- yangi (lnx - An (- ME Lan (dan) and Latin mida) Ho Ly Indutanie fer unit length of by distance D. parallel wire of radices a separated (b) V² Eu= Med Ey Ware dinuction tx direction Y ug for at Elric field ty ah ah rue ... alt=aâx â a VX H4 = d0 +j (as 6=0 :.J=0) duk → 98H, - and content => 7X H₂ = Ed Ey . Taking both sides wil, vXXX H₂ = & 2 (TXE) - and TX OX H = - 7²H and TX E = -2B :. Put and ② , we get, - - 8²H _ . Cople & Hz or D? 1 2 Moko dHz at Scanned with CamScanner cans)