true or false . refraction always involves a change in the speed and direction of a wave

wat is required in order for diffraction to occur?

wat causes wave interference?

True. Refraction always involves a change in the speed and direction of a wave.

To understand what is required for diffraction to occur, we need to look at the nature of waves. Diffraction is the bending or spreading out of waves as they encounter an obstacle or pass through an opening. Diffraction occurs when a wave encounters an obstacle or passes through an opening that is similar in size to its wavelength. To put it simply, for diffraction to occur, the size of the obstacle or opening should be comparable to or smaller than the wavelength of the wave.

Wave interference, on the other hand, is caused by the interaction of two or more waves. When waves meet, they overlap and their amplitudes (heights) add together. This interaction can lead to constructive interference, where the waves reinforce each other and create a larger combined wave, or destructive interference, where the waves cancel each other out and create a smaller or no wave at all.

So, in summary:
- Diffraction requires an obstacle or opening comparable in size to the wave's wavelength.
- Wave interference is caused by the interaction of two or more waves.