Activity: To show that the incident ray, reflected ray and the normal at the point of incidence lie in the same plane.

Materials Required: Plane mirror, holder, ray box, etc.

Procedure: Fix sheet of white paper, a little beyond the edge of the board. Place a plane mirror strip vertically to the paper using a stand. Throw light from a ray box on the mirror. Look at the reflected ray. Mark the incident ray, normal ray and reflected ray. Fold the paper which is beyond the edge of the board. You will observe that the reflected ray is not seen in the folded portion of the chart paper. Now bring the folded portion back to its original position. The reflected ray of light is again seen on the page.

Conclusion: The sheet on the board can be considered as a plane. The incident ray, the reflected ray, the normal at the point of incidence lie in the same plane.

Incident ray, reflected ray and normal at the point of incidence lie in the same plane.