State what is meant by amplitude modulation (AM) in this context.
The signal from the radio station varies in intensity with frequency as shown in Fig. 5.1. State the bandwidth for this signal.
The signal from the radio station varies in intensity with frequency as shown in Fig. 5.1. State the maximum audio frequency broadcast for this signal.
A transmission line with length $45\,\text{km}$ has an attenuation of $2.0\,\text{dB km}^{-1}$ per unit length. The input power to the line is $500\,\text{mW}$. The minimum acceptable signal-to-noise ratio is $24\,\text{dB}$ for background noise of $5.0 \times 10^{-13}\,\text{W}$. Calculate the minimum acceptable power output from the transmission line.
Use your answer in (i) to decide whether the signal can be transmitted along the transmission line.