Calculate the charge density in a certain region, in the following two cases:
the electric field in spherical coordinates is given by:
e(r)=ar^2 r+bcosθ/r θ+cϕ
where a, b and c are constants
the electric field in cylindrical coordinates is given by:
er=a/rr+br θ+cr^2z^2z
where a, b and c are constants

50.)the diagram below represents the wave fronts produced by a point source moving to the right in a uniformmedium. observers are located at points a and b. compared to the wave frequency and wavelength observed at point a, the wave observed at point b has a(1) higher frequency and a shorter wavelength(2) higher frequency and a longer wavelength(3) lower frequency and a shorter wavelength(4) lower frequency and a longer wavelength