Matching Pairs Materials for technical useOnline version What is involved in making a mobile phone? Match the following elements. by Jesús Espinosa 1 How big is it? 2 How much does it cost? 3 What materials is it made of? 4 The outer casing of mobile phones is typically made from... 5 What is it for? 6 How does it work? They work like two-way radios: the phone converts the sounds of your voice into radio signals and transmits them to another phone, which converts them back into sound. plastic (polycarbonate), aluminium and magnesium. Plastic, aluminium and other metals For people to talk to each other from wherever they are. Nowadays the average is more than 5 inches long (12.7 cm). The average price for a free smartphone is currently anywhere between 400€ and 800€.