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Figure 4 shows a block (subsystem) diagram for a radio communication system - AQA - A-Level Physics - Question 3 - 2018 - Paper 8
Question 3
Figure 4 shows a block (subsystem) diagram for a radio communication system. State the letter representing the subsystem in which you might find an induced emf be... show full transcript
Worked Solution & Example Answer:Figure 4 shows a block (subsystem) diagram for a radio communication system - AQA - A-Level Physics - Question 3 - 2018 - Paper 8
Step 1
Step 2
Step 3
Explain why the signal strength at stage D is weak.
Answer
The signal strength at stage D is weak due to attenuation of the electromagnetic wave across the transmission path. Factors contributing to this include energy loss from reflection off the ground, natural topography, and absorption in the atmosphere.
Step 4
Complete the graph in Figure 5 to represent the combined amplitude modulated (AM) signal.
Answer
The combined AM signal graph should show a carrier wave with varying amplitudes corresponding to the modulating sine wave, maintaining the original frequency characteristics while enveloping around the carrier.
Step 5
Suggest whether all these stations can broadcast hi-fi music using the full audio frequency of 20 kHz.
Answer
Not all stations can broadcast hi-fi music using the full audio frequency of 20 kHz. Given the allocated frequency spectrum of 540 kHz to 1600 kHz, there is bandwidth limitation for all stations. Each station would require a bandwidth of at least 20 kHz to transmit the full audio frequency, leading to potential overlap and crosstalk issues.