This question is about electromagnetic waves and their interactions with materials.
Infrared and visible light are both used for carrying signals in optical fibres. State one other region of the electromagnetic spectrum commonly used for wireless communications (such as Wi-Fi or satellite transmissions).
Inside an optical fiber, light relies on reflection to travel.

What is the scientific term for the dashed line shown in the diagram?
Complete the sentences describing how white light interacts with a blue filter. Choose your answers from the following words:
(i) Blue light passes through because it is _________ by the filter.
(ii) Red light does not pass through because it is _________ by the filter.