Question 5
- Define modulation.
- State four advantages of frequency modulation over amplitude modulation.
- State two applications of amplitude modulation.
- Fig. 4 is a diagram showing the carrier and sidebands in amplitude modulation.
Determine the bandwidth required for transmission.
Observation
The reported stated that question 5 (electronic communication) was unpopular among candidates as only a few of them attempted it.
The expected answers were:
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Definition of modulation
The process by which a parameter of a carrier/radio wave is varied in accordance with the information to be transmitted. -
Advantages of frequency modulation over amplitude modulation
- FM is less noisy
- Superior quality
- Higher transmission efficiency
- Less interference
- Higher immunity to noise
- Higher signal-to-noise ratio
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Applications of amplitude modulation
- • Telephony
- • Video transmission
- • Sound transmission over wide coverage
- • Mobile emergency services
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Bandwidth = upper side band – lower side band
= 1001kHz – 999kHz
= 2kHz