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An audio signal given by 25 sin 2π(2000) is used to amplitude-modulate a carrier 60 sin 2π(100,000). What is the modulation index of the resulting AM wave?
- 25%
- 41.6%
- 50%
- 75%
Correct answer: 41.6%
Solution
The modulation index in amplitude modulation is calculated as the ratio of the peak amplitude of the modulating signal to the peak amplitude of the carrier signal. Here, the peak amplitude of the audio signal is 25 and the carrier signal is 60, leading to a modulation index of 25/60, which simplifies to approximately 41.6%.
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