Young's experiment part 1

It is difficult to use the measured values without having information about slit widths. However, some qualitative observations and conclusions can be made.

1. What happens when slits of different separation are used? Explain this observation using what your know about diffraction and interference

2. What happens when the coloured lasers are used? Explain this observation using what you know about diffraction and interference.

3. What happens to the pattern when you move toward or away from the screen?

Consider the relationship: The band length, Δx or b

Where L is the distance from the source (or screen) and d is the slit separation. The band length is the distance of one complete light and dark fringe eg.

Using this relationship and observations what would happen to the band length if

a) green light was replaced with red

b) you moved away from the source

c) the slit separation was made bigger.

When using white light for these observations, colours can be seen. Explain why this occurs.