Geometric Optics
- Prelab 1:
Rearrange
,
as
,
where
.
We can plot and LINEST sinθ1 vs sinθ2, say the slope is m, then
.
- You can also plot and LINEST n1sinθ1 vs sinθ2, and the refractive index, n2 is just the slope.
- Prelab 2:
Given
,
which can be rearranged as
.
We can plot and LINEST 1/S0 vs 1/Si, say the y-intercept is b, then
.
- 1. Measuring the refractive index of the block:
The uncertainty of sinθ is cosθδθ, and δθ should be expressed in radian, not degree.
- 2. Measuring the focal lengths of two lenses:
The uncertainty should be calculated from prelab 2.
Using error propagation, the uncertainty of y (i.e., 1/So) and x (i.e., -1/Si) should be
.
- 3. Building a telescope:
The distance between the two lenses should be equal to the sum of their focal lengths.
The theoretical magnification factor of the telescope is then,
,
with
.
and the measured magnification factor can be determined from measuring the height of an object with and without the telescope:
Fig 1. Magnification Measurement. (Image Credit: Nate Welsh)