Formation of image by a pinhole in Reflection of Light By Different Surfaces – Class 10 Science Experiment
Chapter Name: Reflection of Light By Different Surfaces
Activity Name: Formation of image by a pinhole in Reflection of Light By Different Surfaces
Activity Description:
In this experiment, we explore the formation of an image using a pinhole camera. The pinhole camera is a simple optical device that uses a small hole to project an inverted image of an object onto a screen.
We investigate how the size of the hole affects the clarity of the image formed on the screen.
Required Items:
- Pinhole camera (can be made using a cardboard box)
- Candle
- Screen or white paper
- Drawing materials for the ray diagrams
Step by Step Procedure:
- Set up the pinhole camera by making a small hole in one side of the cardboard box.
- Place the candle on the opposite side of the pinhole.
- Place the screen or white paper on the side of the pinhole with the hole, where the image will be projected.
- Observe the flame of the candle through the pinhole camera and note the appearance of the image on the screen.
- Now, enlarge the hole of the pinhole camera.
- Observe the candle flame again and note the changes in the image formed on the screen.
- Using the observed results, draw ray diagrams to understand the formation of the image in both cases (small hole and big hole).
Experiment Observations:
- With the small hole: The image formed on the screen will be sharper and more focused.
- With the big hole: The image formed on the screen will be blurred and less defined.
Precautions:
- Handle the candle with care to avoid accidents.
- Be cautious with the pinhole camera, especially when enlarging the hole.
- Conduct the experiment in a dimly lit room for better observation.
Lesson Learnt from Experiment:
The experiment demonstrates that a smaller hole in the pinhole camera produces a clearer and more defined image, while a larger hole results in a blurred image. This phenomenon is due to the way light rays from different points on the object diverge and pass through the hole, creating a focused or unfocused image on the screen.
