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suggest / explain
Recall and explain
(a) A cargo ship sails east across the Pacific Ocean, near the equator, from the Philippines to Peru. Its satellite phone works through geostationary satellites, and part of the way across it switches from one satellite to another. Suggest why. (b) Supplement. In the port office, a printer linked by Bluetooth prints from a laptop in the next room, through one wall. From a room four walls away, it prints nothing. Explain why.
suggest: apply what you know to this case. explain: give reasons and connect them to evidence.
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Scope and sources
Cambridge IGCSE Physics 0625 · 2026–2028 v2 · Original learning materials.
Communication with artificial satellites, mainly by microwaves: low-orbit satellites for some satellite phones, geostationary satellites for other satellite phones and for direct broadcast satellite television (3.3.5); Supplement: why mobile phones and wireless internet use microwaves, Bluetooth radio waves, and optical fibres visible light or infrared (3.3.7); digital and analogue signals (3.3.8); a sound sent as a digital or analogue signal (3.3.9); the benefits of digital signals, a higher rate of data and a greater range through accurate regeneration (3.3.10). The regions of the electromagnetic spectrum and their other uses are in Light and the electromagnetic spectrum; total internal reflection in optical fibres is in Refraction; orbits and their periods are in the Space physics modules; how a signal is put onto a carrier wave and how a sound is sampled are not covered.
Apparatus, amounts and times in the experiment are illustrative. Real practical work follows a teacher-approved safety method.
Official Cambridge syllabus