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## Homework Statement

The diagrams below illustrate the formation of a rainbow. Figure 1 shows the general arrangement and Figure 2 shows the path of a ray through a raindrop with the centre of the raindrop is labelled O.

*Figure 1:*

*Figure 2:*

a.)

Where the ray enters the raindrop in Figure 2, mark the angle of incidence i and the angle of refraction, r.

b.)

Figure 2 is drawn to scale. By taking suitable measurements, show that the refractive index of water is about 1.3.

## Homework Equations

[itex]\mu = \frac{\sin i}{\sin r}[/itex]

## The Attempt at a Solution

a.)

^ Have I labelled it correct?

b.)

I measured the angle that I have labelled above and got [itex]i = 25^\circ[/itex] and [itex]r = 35^\circ[/itex] and this gives [itex]\mu = 0.74[/itex]. This is incorrect. The correct answer is [itex]i = 53, \ r = 39, \ \implies \mu = 1.27[/itex]. Where have I gone wrong here?