Radio,Television And Electronic Paper 2, WASSCE (SC), 2019

Question 5

 

  1.          Define modulation.
  2.          State four advantages of frequency modulation over amplitude modulation.
  3.          State two applications of amplitude modulation.
  4.          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:

  1. Definition of modulation
    The process by which a parameter of a carrier/radio wave is varied in accordance with the information to be transmitted.

  2. 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

  3. Applications of amplitude modulation
    • • Telephony
    • • Video transmission
    • • Sound transmission over wide coverage
    • • Mobile emergency services

  4. Bandwidth = upper side band – lower side band
    = 1001kHz – 999kHz
    = 2kHz