During a physics laboratory session, a student investigates the refraction of a ray of light passing through a rectangular transparent block using the pin-pointing method.
The student places two pins, P1P_1P1 and P2P_2P2, to define the path of the incident light ray before it enters the block.
Suggest a suitable minimum distance between pin P1P_1P1 and pin P2P_2P2.
State why placing these pins too close together would lead to inaccuracies in the traced ray.
State two precautions, other than pin separation, that should be taken during this ray-tracing experiment to ensure high accuracy.
The student wants to investigate if the ratio of the sine of the angle of incidence to the sine of the angle of refraction (sinisinr\frac{\sin i}{\sin r}sinrsini) is constant for different values of iii. State five suitable values of the angle of incidence iii that the student could use to thoroughly test this relationship.
216 exam-style questions on CIE IGCSE Physics 3.2 Light, covering 3.2.1a Reflection of light, 3.2.1b Images in a plane mirror, 3.2.2 Refraction of light, 3.2.2a Refraction of light, 3.2.2b Total internal reflection, 3.2.2c Refractive index and critical angle, 3.2.2d Optical fibres, 3.2.3a Converging and diverging lenses, 3.2.3b Ray diagrams and the nature of images, 3.2.3c Virtual images and the magnifying glass, 3.2.3d Correcting long-sightedness and short-sightedness, and 3.2.4 Dispersion of light. Each one has a worked solution and a mark scheme showing where the marks go.