Removing water of crystallisation in Refraction of Light At Plane Surfaces – Class 10 Science Experiment

Chapter Name: Refraction of Light At Plane Surfaces

Activity Name: When acid reacts with metal H2 gas is evolved in Refraction of Light At Plane Surfaces

Activity Description:

In this experiment, we will observe the refraction of light at a plane surface, specifically when light passes through a glass tumbler filled with water and a pencil is placed inside. We will compare the appearance of the pencil when viewed from the side of the glass and from the top of the glass.

Required Items:

1. Glass tumbler
2. Water
3. Pencil

Step by Step Procedure:

1. Take the glass tumbler and fill it with water.
2. Place the pencil inside the glass, ensuring it is completely submerged in the water.
3. Look at the pencil from the side of the glass and observe its appearance.
4. Then, look at the pencil from the top of the glass and note down its appearance from this viewpoint.

Experiment Observations:

• When viewed from the side of the glass, the pencil may appear bent or distorted due to the refraction of light as it passes from air to water and then from water to air again.
• When viewed from the top of the glass, the pencil may appear normal as the light travels straight through the water and does not undergo significant refraction.

Precautions:

1. Ensure that the glass tumbler is clean and transparent for accurate observations.
2. Submerge the pencil completely in water to avoid any air gaps that could affect the observations.
3. Conduct the experiment in a well-lit room to observe the pencil’s appearance clearly.

Lesson Learnt from Experiment:

This experiment demonstrates how light undergoes refraction when passing through different media with varying refractive indices, such as air and water. It illustrates the bending of light rays at the water-air interface, causing the pencil to appear distorted when viewed from the side. However, when observed from the top, where the light passes straight through the water, the pencil appears normal.