I have read somewhere that signal travels as electromagnetic waves in wires near to speed of light. The signals are brought to destination by EM waves. Then what does electrons do? If signals travel as EM waves, then why Resistance and capacitance of net affects the delay? If I have to send a high signal (say 5v), and if net delay is 10us, then should I need to maintain the high voltage signal at source untill it reaches the destination (for 10us) or can I change the signal after some time (say 2us) and send the next signal so that signals will be propagating sequentially and 1st signal reaches the destination after 10us and 2nd signal reaches after 12us?