NCERT Question 5 - Chapter 16 Class 8 - Light

Describe an activity to show that the incident ray, the reflected ray and the normal at the point of incidence lie in the same plane.

Answer

This is actually Activity 16.2 of the NCERT Book. Let’s discuss this

We follow these steps

• Take a white sheet paper and place it on the table
• Let the sheet be a little outside the edge of the table
• Take a comb and close all its openings except the middle
• Hold the comb perpendicular to the sheet of paper
• Now, throw light of the torch from through the opening of the comb
• We can see the incident and the reflected ray on the white sheet
  
  
  
• Now, we make the normal
• Using a scale, we cut the sheet from the point of reflection.
  
  
  
• We can see that incident ray, reflected ray and normal all lie in the chart paper. They are not up or below the chart paper.

Hence, incident ray, reflected ray and normal all lie in the same plane