Exam-style question
Try this first
Explain how amplitude modulation and frequency modulation differ in terms of how the carrier signal is altered.
Model answer
What a good answer should say
- Amplitude modulation (AM) changes the amplitude of the carrier wave while keeping its frequency constant.
- Frequency modulation (FM) changes the frequency of the carrier wave while keeping its amplitude constant.
- The key difference is therefore which carrier property is varied.
- AM is often used where simple demodulation is required, whereas FM is chosen for better noise immunity and higher fidelity.
Explanation
Why this works
The answer defines both AM and FM, identifies the key difference (amplitude versus frequency variation), explains when each technique is typically applied (simple demodulation for AM, noise‑immune transmission for FM), and concludes by summarising the distinguishing feature. This demonstrates a clear understanding of the concepts and their practical implications, directly testing the learning objective.
Common mistake
No common mistake is linked to this question yet.