The wave nature of light is demonstrated by which of the following ?*1 pointThe photoelectric effectDiffractionColourThe speed of light

The wave nature of light is demonstrated by Diffraction.

Here's why:

1. The Photoelectric Effect: This actually demonstrates the particle nature of light (photons), not its wave nature.

2. Diffraction: This is the bending of light waves around obstacles or the spreading of light waves after they pass through a narrow opening. This phenomenon can only be explained if light is considered as a wave.

3. Colour: While colour is a property of light, it doesn't specifically demonstrate the wave nature of light. It's more related to the frequency of the light wave.

4. The Speed of Light: This is a constant (in a vacuum) and while it's an important property of light, it doesn't specifically demonstrate the wave nature of light.

So, the correct answer is Diffraction.