Question 1: Define the term 'reflection' as it applies to light waves.

Answer: Reflection is the process where light waves bounce off a surface and change direction while remaining in the same medium.

Question 2: State the law of reflection.

Answer: The law of reflection states that the angle of incidence is equal to the angle of reflection, measured with respect to the normal.

Question 3: Explain why the angles of incidence and reflection are measured relative to the normal.

Answer: Because the normal is an imaginary line perpendicular to the surface at the point of incidence, measuring angles relative to it provides a standard reference for comparing the directions of incident and reflected rays.

Question 4: A ray of light strikes a mirror at an angle of 30° to the normal. What is the angle of reflection?

Answer: 30°

Question 5: Identify three common surfaces where reflection of light occurs in daily life.

Answer: Mirrors, water surfaces, and glass windows.

Question 6: Describe a simple experiment to demonstrate the law of reflection using a plane mirror and a light source.

Answer: Set up a plane mirror on a stand and shine a laser or light beam at it at a known angle. Use a protractor to measure the angle of incidence and then observe the reflected beam. Confirm that the angle of reflection equals the angle of incidence relative to the normal, which can be marked or measured with a protractor.

Question 7: A car’s side mirror is convex to provide a wider field of view. How does the curvature of the mirror affect the reflection of light and the image produced?

Answer: The convex curvature causes the reflected rays to diverge, resulting in a smaller, wider-angle image that helps the driver see more area but makes objects appear smaller and farther away.

Question 8: Explain why smooth, shiny surfaces produce clear reflections, whereas rough surfaces produce diffuse reflections.

Answer: Smooth, shiny surfaces reflect light in a consistent direction because their surface irregularities are minimal, resulting in clear images. Rough surfaces scatter light in many directions, causing diffuse reflection and blurry or no clear images.

Question 9: In a practical situation, why is it important for the normal line to be accurately drawn when measuring angles of incidence and reflection?

Answer: Because the measurement of angles depends on the normal, an inaccurate normal leads to incorrect angles, which can affect the understanding of the reflection behaviour.