2008
VLF Radio Signals
by rike_The source of most natural radio signals is lightning. When a lightning bolt strikes, a massive amount of charge is moved and this acts in much the same way as moving charge in a radio transmitting antenna. The frequencies emitted by lightning range from 0 Hz to over 100 kHz with all frequencies being emitted simultaneously with the visible flash of lightning.
2005
1
(2 marks)