EXPERIMENT 112
THIN LENSES
ANALYSIS
Lenses play an important part on the discovery of various things we know
today. Some examples are the telescopes and microscopes which use lenses to
magnify things from a finite or infinite distance. Without lenses, the said examples
will not be possible. In the last experiment, we discussed all about reflection. But in
this experiment, we will be dealing refraction, which is also a characteristics of a
wave.
A piece of glass of finite thickness with two spherical boundaries is a lens. If
the thickness of the lens is much smaller than the diameter of the lens, we call it
a thin lens. Thin lenses can be converging or diverging. Converging lenses, as
shown in Fig. 1, are thicker in the middle than near the edges, and diverging lenses
are thicker near the edges than in the middle. A thin lens has two focal points,
located on the optical axis, a distance f from the center of the lens on either side of
the lens.
Fig. 1. The Ray diagram of a converging lens.
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, Convex lens is used on our experiment which has middle-part thicker. Focal
length's relation to the object and the image is given by the thin lens equation where
focal length is the difference on product and sum of the object and image distance
from the lens. The think lens equation can be used with either converging (convex)
or diverging (concave) lenses that are thin and it relates the object distance (s), the
image distance (s’), and the focal length of the lens f.
1 1 1
= + (1)
𝑓 𝑠 𝑠′
The magnification of the lens is the ratio of the image height and the object
height, and is also related to the distances of the object and image from the lens.
𝑠′ ℎ𝑖
𝑚=𝑚= = 𝑚= (2)
𝑠 ℎ𝑜
To start with this experiment, as shown in Fig. 2, we were given 1 piece of
Optical bench, 1 piece of Image screen, 1 piece of Light source, and 2 pieces of
Convex lens. Also, we were advised to be careful in handling the optical bench and
convex lenses.
This study source was downloaded by 100000899606070 from CourseHero.com on 02-15-2026 04:27:21 GMT -06:00
https://www.coursehero.com/file/44962065/PHYS101L-E112pdf/
THIN LENSES
ANALYSIS
Lenses play an important part on the discovery of various things we know
today. Some examples are the telescopes and microscopes which use lenses to
magnify things from a finite or infinite distance. Without lenses, the said examples
will not be possible. In the last experiment, we discussed all about reflection. But in
this experiment, we will be dealing refraction, which is also a characteristics of a
wave.
A piece of glass of finite thickness with two spherical boundaries is a lens. If
the thickness of the lens is much smaller than the diameter of the lens, we call it
a thin lens. Thin lenses can be converging or diverging. Converging lenses, as
shown in Fig. 1, are thicker in the middle than near the edges, and diverging lenses
are thicker near the edges than in the middle. A thin lens has two focal points,
located on the optical axis, a distance f from the center of the lens on either side of
the lens.
Fig. 1. The Ray diagram of a converging lens.
This study source was downloaded by 100000899606070 from CourseHero.com on 02-15-2026 04:27:21 GMT -06:00
https://www.coursehero.com/file/44962065/PHYS101L-E112pdf/
, Convex lens is used on our experiment which has middle-part thicker. Focal
length's relation to the object and the image is given by the thin lens equation where
focal length is the difference on product and sum of the object and image distance
from the lens. The think lens equation can be used with either converging (convex)
or diverging (concave) lenses that are thin and it relates the object distance (s), the
image distance (s’), and the focal length of the lens f.
1 1 1
= + (1)
𝑓 𝑠 𝑠′
The magnification of the lens is the ratio of the image height and the object
height, and is also related to the distances of the object and image from the lens.
𝑠′ ℎ𝑖
𝑚=𝑚= = 𝑚= (2)
𝑠 ℎ𝑜
To start with this experiment, as shown in Fig. 2, we were given 1 piece of
Optical bench, 1 piece of Image screen, 1 piece of Light source, and 2 pieces of
Convex lens. Also, we were advised to be careful in handling the optical bench and
convex lenses.
This study source was downloaded by 100000899606070 from CourseHero.com on 02-15-2026 04:27:21 GMT -06:00
https://www.coursehero.com/file/44962065/PHYS101L-E112pdf/
