The majority of antenna designs are based on the resonance principle. This relies on the behaviour of moving electrons, which reflect off surfaces where the dielectric constant changes, in a fashion similar to the way light reflects when optical properties change. In these designs, the reflective surface is created by the end of a conductor, normally a thin metal wire or rod, which in the simplest case has a feed point at one end where it is connected to a transmission line. The conductor, or element, is aligned with the electrical field of the desired signal, normally meaning it is <answer>perpendicular</answer> to the line from the antenna to the source (or receiver in the case of a broadcast antenna).
How would you place the conductor in relation to the signal you wished to obtain?
perpendicular