1) A student uses a ray box and a semicircular glass block, as shown below, to investigate refraction.

She obtains the following results:

Which set of results is likely to be incorrect?

2) 2024 S4 EOY P1 Q09

A ray of monochromatic light in air is incident on transparent blocks of different shapes.

Which diagram below does not show the correct path of the ray of light through the block?

3) A ray of light is shown entering substance J from air.

The refractive index of J is given by:

4) 2023 S3 EOY P1 Q08

A scientist conducts an experiment to find the critical angle at the boundary between two mediums. The scientist uses three mediums of refractive indices 1.0, 1.2 and 1.6.

Which is not a possible critical angle?

5) 2025 S4 EOY P1 Q10

A ray of light travels from glass of refractive index 1.5 into a transparent material. The angle of incidence in glass is 45°, and the angle of refraction in the material is 60°. The speed of light in vacuum is 3.0 × 10⁸ m s^-1.

What is the speed of light in the transparent material?