Revise GCSE Physics


P1f Data Transmission

  1. Can you give examples of everyday uses of infrared radiation for purposes other than cooking or heating?
  2. How do infrared signals carry information to control electrical or electronic devices?
  3. Describe how infrared radiation is used in automatic doors.
  4. How is infrared radiation used in short distance data links?
  5. What form does the infrared signal from a remote control take?
  6. What is a passive infrared sensor?
  7. How does a passive infra sensor detect the presence of a person?
  8. How do thermal cameras work?
  9. What is a signal?
  10. What is data?
  11. What is transmission?
  12. What types of signal do we need to know about?
  13. What is meant by an analogue signal?
  14. What is meant by a digital signal?
  15. Does that mean that you can only ever use a digtial signal to transmit the numbers 1 or 0?
  16. How would you explain the main differences between an analogue signal and a digtial signal?
  17. What is attenuation of a signal?
  18. What effect does attenuation have on a signal?
  19. Why is attenuation a problem?
  20. Can attenuation be fixed?
  21. What is the problem with just amplifying an attenuated signal?
  22. What is noise on a signal?
  23. What causes noise to be added to a signal?
  24. Why is noise a problem?
  25. Can noise ever be removed from a signal?
  26. How does this affect amplification?
  27. Why is noise less of a problem on a digital signal?
  28. Can noise be removed from a digital signal?
  29. What are the main differences between analogue and digital when it comes to noise and attenuation etc.?
  30. Why has the UK television service be switched from analogue to digital?
  31. What does this digital signal represent?
  32. What does DAB stand for?
  33. Why do radio stations that are broadcasting in the same area need to broadcast their signals using different frequencies (of the radio waves that carry the signals)?
  34. What are the advantages and disadvantages of DAB broadcasts?
  35. What are the advantages of using optical fibers?
  36. What is multiplexing?
  37. What is the difference between time division multiplexing and wavelength division multiplexing?
  38. Why do optical fibers not suffer from interference on the received signal?
  39. Are there any disadvantages to using optical fibers?
  40. How are optical fibers actually used to carry signals?