Question

An antenna is connected to a car battery. Will the antenna emit electromagnetic radiation? Why or why not? Explain

Answer 1

Only during hookup and disconnect when the current is changing. To get a radiating wave you need changing current (in the simplest case, an accelerating charge radiates; look that up in your text or Google it. Normally you radiate using a sinusoidal signal of a frequency with a wavelength matched to the antenna. However using Fourier transforms, any old changing signal can be made up of sine waves. However just a steady direct current just gives stationary electric and magnetic fields, no Poynting vector, no radiated signal.

Answer 2

This might help:
http://www.youtube.com/watch?v=IWVPJSoJDzA
and this:
http://hyperphysics.phy-astr.gsu.edu/hbase/waves/emwv.html

Answer 3

Good question by the way :)