C3 Flashcards
Why are Radio waves better than X-rays for use in mobile phone communications?
Radio waves have longer wavelength and travel further distances
Why are Radio waves better than ultra-violet waves for use in Wi-Fi?
Radio waves have longer wavelength and can pass through walls
Give a disadvantage of using microwaves in satellite communications
Upload signals need to be amplified as the received signal is weak
Give two advantages of using microwaves in satellite communications
carry large amounts of information
can pass through the Earth’s atmosphere
Give two disadvantages of using microwaves or radio waves in mobile communications
Signal disruption by buildings and stormy weather
Data is not secure and can be hacked
What is the name of the process used by Bluetooth to reduce interference and limit data loss?
frequency hopping
Give two advantages of Bluetooth signal transfers
Does not require line of sight
Can connect to more than one device
Give a disadvantage of Bluetooth signal transfers
Can only transmit over a short range
Give four disadvantages of infrared signals
Affected by moisture in the air
Affected by direct sunlight
Can only operate over a short distance
Only works with one device at a time
Give two advantages of using infrared signals
Does not interfere with other devices
Uses a high frequency so gives better and clearer communications
True or false:
Infrared carries more energy (information) than Bluetooth
True
Why does IR carry more energy (information) than Bluetooth
It uses a higher frequency
True or false:
Bluetooth has a smaller bandwidth than infrared
True
Give two advantages of using radio/microwaves for Wi-Fi signals
Can transmit over long distances
Can pass through walls
Give a disadvantage of using radio/microwaves for Wi-Fi signals
Uses more power so leads to shorter battery life on connected devices
