Final answer:
Radio stations transmit signals over long distances using high frequency in the Mega Hertz range, with FM radio operating at 88 to 108 MHz and AM radio at 540 to 1600 kHz. While transmission power in kilowatts or megawatts is also a factor, frequency is critical for signal reach and integrity.
Step-by-step explanation:
For radio stations to send signals far from their origins, they primarily use High Frequency (Mega Hertz). In the context of radio broadcasting, AM radio signals operate in the frequency range of 540 to 1600 kHz, which allows for long distance transmission. Meanwhile, FM radio signals operate at higher frequencies in the range of 88 to 108 MHz. These frequencies are part of the radio frequency region of the electromagnetic spectrum, which ranges from 3 kHz to 300 GHz. While the power output of a radio transmitter, measured in kilowatts or megawatts, is important for determining the potential reach of a broadcaster's signal, it is the frequency at which the signal is transmitted that plays a key role in its propagation characteristics.
In the case of AM radio, the amplitude of the carrier wave is modulated to vary with the audio signal, maintaining a constant frequency. On the other hand, FM radio maintains a constant amplitude but varies the frequency of the carrier wave to transmit the audio signal. This variance in frequency for FM radio is within the Mega Hertz range, which is essential for its ability to carry signals over considerable distances without losing the integrity of the transmission.