A magnetic dipole m(t) = m_0*cos(ωt) can be
described as current density j(r,t) = −cm(t) × ∇δ(r) at it's
origin. Calculate
(a) the retarded potentials Φ(r,t) and A(r,t)
(b) the electric/magnetic fields E and B as well as
their simplifications for far and near field
(c) the Poynting vector S in far field as well as the
whole emitted power
A magnetic dipole m(t) = m_0*cos(ωt) can be described as current density j(r,t) = −cm(t) ×...
1) A Hertzian dipole antenna is a short conducting wire carrying an approximately constant current over its length If such a dipole is placed along the z-axis with its midpoint at the origin, and if the current flowing through it is i(t) ż lo cosot, assume I to be sufficiently small so that the observation point is approximately equidistant to all points on the dipole; that is, assume RR then the corresponding magnetic field is described by: olk2 sin e...
how did we get the following equation (1.9) from maxwells equations at e at where p is the density of free charges and j is the density of currents at a point where the electric and magnetic fields are evaluated. The parameters and are constants that determine the property of the vacuum and are called the electric permittivity and magnetic permeability respectively The parameter c-1/olo and its numerical value is equal to the speed of light in vacuum,c 3 x...
A large, flat sheet carries a uniformly distributed electric current with current per unit widthJs. This current creates a magnetic field on both sides of the sheet, parallel to the sheet and perpendicular to the current, with magnitude B- 0's. If the current is in the y direction and oscillates in time according to 2 /max (cos ωガーJmax[cos (-wtjj the sheet radiates an electromagnetic wave. The figure below shows such a wave emitted from one point on the sheet chosen...
can help solving question 28a-d? Do we use E=cB or dE/dt = - dB/dt for question a? waves of Ireny means of communication? 34. 28. A large, flat sheet carries a uniformly distributed electric current with current per unit width ),. This current creates Problems nd tic nt ic e, n, f T- 1. a magnetic field on both sides of the sheet, parallel to the sheet and perpendicular to the current, with magnitude B = Mo J. If the...
Consider a cylindrical capacitor like that shown in Fig. 24.6. Let d = rb − ra be the spacing between the inner and outer conductors. (a) Let the radii of the two conductors be only slightly different, so that d << ra. Show that the result derived in Example 24.4 (Section 24.1) for the capacitance of a cylindrical capacitor then reduces to Eq. (24.2), the equation for the capacitance of a parallel-plate capacitor, with A being the surface area of...