Reflected Ray in Reflection of Light – Class 7 Science Experiment

Chapter Name: Reflection of Light

Activity Name: Reflected Ray in Reflection of Light

Activity Description:

This experiment focuses on understanding the behavior of reflected light rays using a mirror strip and a sheet of blank paper. Students draw a line segment (AC) across the middle of the paper and a perpendicular line (Normal) bisecting AC at point B. They then draw additional lines at angles of 30° and 60° on both sides of the Normal.

The mirror strip is placed vertically on segment AC, with its reflecting surface facing the Normal. A light ray is directed along line 4 (labeled in figure 4b) to act as the incident ray. Observations are made to see where the reflected ray falls concerning the drawn lines. The experiment explores the concepts of Angle of Incidence (∠i) and Angle of Reflection (∠r).

Required Items:

1. Sheet of blank paper
2. Mirror strip with a reflecting surface
3. Slit to allow light ray passage
4. Drawing instruments (ruler, protractor)

Step by Step Procedure:

1. Draw line segment AC across the middle of the paper.
2. Draw the Normal, a straight line perpendicular to AC, bisecting it at point B.
3. Draw two lines on each side of the Normal, forming angles of 30° and 60° with the Normal.
4. Place the mirror strip vertically on segment AC with its reflecting surface facing the Normal.
5. Use the slit to direct a light ray along line 4, making it the incident ray.
6. Observe and record where the reflected ray falls concerning the drawn lines.
7. Repeat the above step for different incident rays along lines 1, 2, 3, and the Normal.

Experiment Observations:

• The students record where the reflected rays fall concerning the drawn lines for different incident rays.

Precautions:

1. Handle the mirror strip and slit carefully to avoid any damage or injury.
2. Ensure the mirror strip’s reflecting surface faces the Normal throughout the experiment.
3. Use proper safety measures while working with light sources.

Lesson Learnt from Experiment:

The experiment helps students understand the principles of reflection of light, particularly the Angle of Incidence and the Angle of Reflection. They observe that the angle of reflection is equal to the angle of incidence, and the reflected ray follows the law of reflection.

In this activity on reflection of light, students use a mirror strip and a blank paper to explore the behavior of reflected light rays. By observing the angles at which the reflected rays fall in comparison to the incident rays, they learn about the Angle of Incidence and the Angle of Reflection. The experiment deepens their understanding of the principles of reflection and the law of reflection.