<P> Finally, at radio wavelengths longer than 10 meters or so (about 30 MHz), the air in the lower atmosphere remains transparent to radio, but plasma in certain layers of the ionosphere begins to interact with radio waves (see skywave). This property allows some longer wavelengths (100 meters or 3 MHz) to be reflected and results in shortwave radio beyond line - of - sight . However, certain ionospheric effects begin to block incoming radiowaves from space, when their frequency is less than about 10 MHz (wavelength longer than about 30 meters). </P> <P> Radio waves have the least amount of energy and the lowest frequency . When radio waves impinge upon a conductor, they couple to the conductor, travel along it and induce an electric current on the conductor surface by moving the electrons of the conducting material in correlated bunches of charge . Such effects can cover macroscopic distances in conductors (such as radio antennas), since the wavelength of radiowaves is long . </P> <P> Microwaves are a form of electromagnetic radiation with wavelengths ranging from as long as one meter to as short as one millimeter; with frequencies between 300 MHz (0.3 GHz) and 300 GHz . </P> <Table> <Tr> <Td> </Td> <Td> This section is empty . You can help by adding to it . (October 2017) </Td> </Tr> </Table>

Which of the following electromagnetic wave is emitted as heat