Explain the phenomenon of refraction of light using a diagram and identify its key components and related optical effects.

i) What phenomenon does the diagram illustrate?
The diagram illustrates the phenomenon of refraction of light.

ii) Identify each of the parts labeled I, II, III, IV and V.

• I: Normal
• II: Incident ray
• III: Angle of incidence
• IV: Refracted ray
• V: Angle of refraction

iii) Explain why an object at the bottom of a pond appears closer to the surface than it actually is.
When light rays from an object at the bottom of a pond travel from water (a denser medium) into air (a rarer medium), they bend away from the normal. An observer's eye traces these refracted rays back in a straight line, making the object appear to be at a shallower position than its actual depth. This creates a virtual image that is closer to the surface.