Question

A standing wave is a wave that appears fixed or stationary in space.

true or false ??? help please

Answer 1

yes it is stationary not propagating any energy standing still everywhere

Answer 2

yes true,

when two progressive waves having same amplitude ,same period,same wavelength and travelling in same direction along same line but in opposite direction interfere with each other,then the resultant of the two waves can neither move in forward or backward direction and hence appear as stationary or standing waves
hope it helps
^_^

Answer 3

just as sgholap100 stated, its the cancelling effect of 2 waves on a conductor. however, the 2 waves dont have to be equal in amplitude. this will usually be the case when transmitting radio signals. also known as reflected power or, vswr(voltage standing wave ratio) with respect to rf propagation, its used to determine the efficiency of an antenna or to determine if the antenna and the transmitter are properly impedance matched. you have to know the wattage output of the transmitter and, by using a through line watt meter, measure the amount of reflected power "standing" on the antenna. then use a logarithm to convert the watts reflected to decibels. since no antenna is capable of 100% efficiency, there will always be a measure of reflected power. vswr is a vital check you should make when troubleshooting a radio that has suddenly stopped transmitting or receiving properly.
hope my garble was useful. :)