70. In radio-communication, the signals emitted by transmitting antenna are reflected on A.Stratosphere B.Ozonosphere C.Ionosphere D.Troposphere
Option C Solution: The lower atmosphere is more or less transparent to radio waves. However, the ionosphere reflects back the radio waves. Thus, a signal emitted by an antenna from a certain place can be received at another place on the surface of Earth in the following two ways: ground wave propagation and sky wave propagation.
