ADMICRO

Read the following passage and choose the best answer (A, B, C, D):
Most households in the UK will have a broadband connection and a lot of those  houses will also have experienced connection or speed issues. But what if there was a way to connect to the internet and benefit from a direct connection with much faster speeds? Enter Li-Fi.  Li-Fi stands for Light Fidelity and is a Visible Light Communications (VLC) system which runs wireless communications that travel at very high speeds. With Li-Fi, your light blub is essentially your router. It uses common household LED light bulbs to enable data transfer, boasting speeds of up to 224 gigabits per second.  Li-Fi and Wi-Fi are quite similar as both transmit data electromagnetically. However, Wi-Fi uses radio waves, while Li-Fi runs on visible light waves. This means that it accommodates a photo-detector to receive light signals and a signal processing element to convert the data into “streamable” content. For example, data is fed into an LED light bulb, it then sends data at rapid speeds to the photo-detector. The tiny changes in the rapid dimming of LED bulbs is then converted by the “receiver” into electrical signal. The signal is then converted back into a binary data stream that we would recognise as web, video and audio applications that run on internet-enabled devices.  While some may think that Li-Fi with its 224 gigabits per second leaves Wi-Fi in the dust, Li-Fi’s exclusive use of visible light could halt a mass uptake. Li-Fi signals cannot pass through walls, so in order to enjoy full connectivity, capable LED bulbs will need to be placed throughout the home. Not to mention, Li-Fi requires the light bulb is on at all times to provide connectivity, meaning that the lights will need to be on during the day. Additionally, where there is a lack of light bulbs, there is a lack of Li-Fi internet so Li-Fi does take a hit when it comes to public Wi-Fi networks.  However, using Li-Fi instead of Wi-Fi, you’ll negate lots of security problems associated with shared and often overloaded broadband networks. It will also be advantageous in areas where radio frequency waves do not reach. Due to its impressive speeds, Li-Fi could make a huge impact on the internet of things too, with data transferred at much higher levels with even more devices able to connect to one another. 
7. Which of the following statements is TRUE, according to the passage?

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ZUNIA12
ZUNIA9
AANETWORK