Aussie Maths & Science Teachers: Save your time with SmarterEd
Which type of satellite is commonly used to broadcast TV signals?
`D`
`=>D`
Television programs that show high levels of activity often have lower picture quality.
This is because television signals are transmitted using
`B`
→ Modern television signals are transmitted using digital modulation, so the answer must be A or B.
→ The lower picture quality is the result of the TV being unable to decompress the highly compressed signal quickly.
`=>B`
Outline benefits of digital signal transmission. (3 marks)
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Benefits of digital signal transmission include:
→ Immunity to transmission noise and interference (clearer signal)
→ Signal can be boosted or regenerated along the transmission path (reduced attenuation)
→ Can be encrypted to be kept secure and private
→ Signals can be processed and multiplexed (multiple messages can be sent along the same channel simultaneously)
→ Error detection and correction is possible
→ Cheaper than analogue transmission
→ Signal can be compressed
→ Signal can be stored and further processed
Benefits of digital signal transmission include:
→ Immunity to transmission noise and interference (clearer signal)
→ Signal can be boosted or regenerated along the transmission path (reduced attenuation)
→ Can be encrypted to be kept secure and private
→ Signals can be processed and multiplexed (multiple messages can be sent along the same channel simultaneously)
→ Error detection and correction is possible
→ Cheaper than analogue transmission
→ Signal can be compressed
→ Signal can be stored and further processed
Discuss methods for increasing the signal strength of a receiving antenna. (3 marks)
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→ Amplification: Amplifies the sound, however this could include unwanted background noise.
→ Antenna tuning: The antenna can be tuned to the frequency of interest. This can be done by adjusting the length of the antenna, however this may not be practical in some scenarios.
→ Directional antenna can focus the signal to increase strength however misalignment could result in losing the signal entirely.
→ Amplification: Amplifies the sound, however this could include unwanted background noise.
→ Antenna tuning: The antenna can be tuned to the frequency of interest. This can be done by adjusting the length of the antenna, however this may not be practical in some scenarios.
→ Directional antenna can focus the signal to increase strength however misalignment could result in losing the signal entirely.