(a) Fig. 4.1 shows light passing through a triangular glass prism. [Figure 4.1]

1. (a)(i)State the value of the angle of incidence at point P. angle of incidence =[1]
2. (a)(ii)Draw the normal and the angle of incidence at point R. Label the angle of incidence.[2]
3. (a)(iii)State two conditions needed so that no light refracts from the glass into the air at point Q. 1 2[2]
4. (b)(i)Information is sent across the internet using pulses of visible light through long, thin glass fibres and electrical signals through copper wires. State the name of one other type of electromagnetic radiation used to transmit information through long, thin glass fibres.[1]
5. (b)(ii)Suggest two advantages of using glass fibres rather than copper wires to transmit information from the internet. 1 2[2]

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