The speed of light in air is 3.0 × 108 m/s.
The critical angle for light in a transparent glass material placed in air is 53∘53^\circ53∘.
What is the speed of light in the glass material?
1.8×108 m/s1.8 \times 10^8\text{ m/s}1.8×108 m/s
2.4×108 m/s2.4 \times 10^8\text{ m/s}2.4×108 m/s
3.8×108 m/s3.8 \times 10^8\text{ m/s}3.8×108 m/s
5.0×108 m/s5.0 \times 10^8\text{ m/s}5.0×108 m/s
100 exam-style questions on CIE IGCSE Physics 3.2.2 Refraction of light. Each one has a worked solution and a mark scheme showing where the marks go.