Question 1: Define the law of reflection in your own words.

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

Question 2: Explain why the normal line is important in analysing reflection.

Answer: The normal line is an imaginary line perpendicular to the surface at the point of incidence; it is used as a reference to measure angles of incidence and reflection.

Question 3: What is the difference between regular and diffuse reflection?

Answer: Regular reflection occurs on smooth surfaces producing a clear image, while diffuse reflection occurs on rough surfaces scattering light in many directions.

Question 1: A ray of light strikes a mirror at an angle of 30° to the normal. Calculate the angle of reflection.

Answer: 30°

Question 2: If the incident ray makes an angle of 45° with the normal, what is the angle of reflection? Also, state the law of reflection that applies.

Answer: 45°. The law of reflection states that the angle of incidence equals the angle of reflection.

Question 3: A light ray hits a mirror and reflects at an angle of 60°. If the incident ray was at an angle of 60° to the normal, confirm whether this complies with the law of reflection.

Answer: Yes, because the angle of incidence and reflection are both 60°, satisfying the law of reflection.

Question 1: Describe a simple experiment to demonstrate the law of reflection using a plane mirror and a ray box. Include the key variables involved and safety precautions.

Answer: Set up a plane mirror on a smooth surface. Shine a narrow beam of light from the ray box onto the mirror at a known incident angle. Use a protractor to measure the angles of incidence and reflection relative to the normal. Key variables include the incident angle, reflection angle, and the position of the mirror. Safety precautions include avoiding direct eye exposure to the ray box and ensuring the work area is free of obstructions.

Question 1: A person observes their reflection in a mirror placed vertically on a wall. The incident light strikes the mirror at an angle of 25° to the normal. Explain the path of the reflected light and how the law of reflection applies.

Answer: The incident light approaches the mirror at 25° to the normal, and according to the law of reflection, the reflected light will also leave at 25° to the normal in the opposite direction, maintaining the angle equality.

Question 1: Explain how the principles of light reflection are utilised in the design of optical telescopes.

Answer: Optical telescopes use mirrors to reflect and focus light from distant objects, employing the law of reflection to direct light accurately to the eyepiece for clear viewing.

Question 2: Describe a safety consideration when working with mirrors and reflected light in a laboratory setting.

Answer: Avoid direct exposure to intense reflected light, which can cause eye damage; use proper eye protection and ensure the light source is controlled.