Diamonds, cubic zirconia and silicon carbide can be used as gemstones in jewellery.
The speed of light in these materials is shown in the table.
| diamond | cubic zirconia | silicon carbide |
speed of light/ms−1 | 1.24 × 108 | 1.39 × 108 | 1.15 × 108 |
In order to identify the material used, a ray of light is directed towards a boundary between air and the gemstone.
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Deduce the material used for the gemstone.
Diamonds are cut into different shapes so that they ‘sparkle’ when light shines on them.
The diagram shows a ray of light entering a diamond and incident on a boundary between diamond and air.
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i) Add to the diagram to show the path of the ray of light as it leaves this boundary. Your answer should include a calculation.
(4)
ii) Explain what would happen to the ray at this boundary if the material used was silicon carbide instead of diamond.
(2)
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