Ray Optics-Lab Report (Lab Report Sample)

Student’s Name
Professor’s Name
Course
Date
Ray Optics-Lab Report
Converging lenses are designed in such a way that parallel light incident on either side of the lens penetrates through one point on the opposite side. This point of convergence is referred to as the focal point and it is denoted by letter f. The convergence of the light at the focal point is caused by refraction at both surfaces of the lens (Hunter and Constance 13). Rays that strike the lens at its center pass through without undergoing refraction, hence they are transmitted through the focal point in straight line.
Different materials have different refractive indices, which depend on the magnitude of dispersion of light of each material. Some of the materials whose refractive indices have been experimented and established are polycarbonate (n=1.586), finalite (n=1.60), diamond (n=2.417), polystyrene (n= 1.55-1.59), heavy flint glass (n=1.67), and sapphire (n=1.77) (Batsanov). The location of an object relative to the focal point determines the nature and size of the image formed by the converging lens. For instance, when the object is placed at 2F from the lens, the image is real, inverted, and same size as the object. Contrary, placing the object closer to F produces a virtual, upright, and magnified image (Yu et al.).
Figure SEQ Figure \* ARABIC 1: Convergence of light at the focal point of the lens (Hunterand Constance 23).
Experiment 1: Determination of n
Goal: This experiment intends to establish if the materials making the converging lenses have the same converging index of refraction
Materials
1 1 Incandescent source box
2 2 converging lenses
3 1 screen
4 1 index card
5 One 12” ruler
Procedure
The lamp, screen, and converging lenses are set up on the optical track. The lamp was then plugged in and the lens and screen arranged to obtain an image of the source on the screen. The heights of each apparatus were adjusted to ensure a clear image was captured on the screen. The apparatus was further adjusted to produce an inverted and real image of the source on the screen which is approximately the same size as the object. The image and object distance were measured and recorded. The lens and screen were then rearranged to ensure the image I real and inverted but has magnification of 1.5. The image and object distances were measured and recorded.
Experiment 2: Building a telescope
Procedure
The incandescent source and the first lens, 20 cm, were set up, with lens being placed at approximately the midpoint. The screen was placed and adjustments done until an image forms on it. The second lens of 10 cm was placed after the screen and adjusted so that one could see the screen in focus when looked through the second lens.
Results
Experiment 1 Results
Values for the real and inverted images
Type of distance

Real and inverted image of the same size (cm)

Real and inverted image of 1.5 magnification (cm)

Object distance

95.7-72.3 = 23

97.7-78.6 = 19.1

Image distance

72.7-54.5 = 18.2

78.6-54.5 = 24.1

Focal length



Using the image and object distance values in experiment 1, the thin lens equation, 1/f = 1/p + 1/i , can be rewritten as,
1/23 + 1/18.2 = 0.09842 = 1/f
Therefore, the value of f = 10.2 cm
Experiment 2:
The image is real
The first lens is placed 94 cm on the tract
The second lens us 72.5 cm on the track
The bottle of water is 44 cm
The lens maker’s equation is given as 1/f = (n-1) (1/R1 – 1/R2); where n = index of refraction, f = focal length, and R1 and R2 radii of curvature of the two lenses.
Using the above equation 1/10.2 = (n-1)