Question 1: Define refraction of light.

Answer: Refraction is the bending of light as it passes from one transparent medium to another due to a change in its speed.

Question 2: Explain why light bends when it passes from air into glass.

Answer: Light bends because its speed changes when passing between media of different densities, causing a change in direction according to Snell's Law.

Question 3: What is the refractive index of a medium, and how is it related to refraction?

Answer: The refractive index measures how much light slows down in a medium; a higher refractive index means greater bending of light at the interface.

Question 1: A ray of light passes from air (refractive index = 1.00) into glass (refractive index = 1.50) at an incident angle of 30°. Calculate the angle of refraction inside the glass using Snell's Law.

Answer: 20°

Question 2: If the angle of incidence in air is increased to 45°, what is the new angle of refraction in the glass? (Refractive indices: air = 1.00, glass = 1.50)

Answer: 30°

Question 1: Describe a simple experiment to demonstrate the refraction of light using a rectangular glass block and a laser pointer. Include variables that need to be controlled.

Answer: Use a laser pointer to shine a beam through a rectangular glass block on a flat surface. Vary the angle of incidence and record the angle of refraction. Control variables such as the medium's temperature, surface cleanliness, and ensuring the laser beam remains steady. Use safety precautions such as wearing eye protection and avoiding direct eye contact with the laser.

Question 2: Identify at least two safety precautions that should be taken when conducting experiments involving light refraction.

Answer: Wearing eye protection when using lasers and ensuring the laser beam is directed away from eyes and reflective surfaces.

Question 1: A student measures the angle of incidence in air as 40° and the corresponding angle of refraction in a plastic block as 26°. The refractive index of the plastic is calculated to be approximately 1.52. Explain how this data supports the concept of refraction.

Answer: The data shows that as light enters the plastic from air, its speed decreases, causing it to bend towards the normal. The calculated refractive index aligns with the theoretical value, confirming that different media cause light to bend due to changes in its speed.

Question 1: Describe how the principle of refraction is utilised in the design of lenses for eyeglasses or microscopes.

Answer: Lenses bend light to focus or diverge rays, correcting vision or magnifying objects by precisely controlling refraction based on their shape and material.

Question 2: Explain why the phenomenon of refraction is important in the development of fibre optic communication technology.

Answer: Refraction allows light signals to be internally reflected within the fibre, enabling efficient and high-speed data transmission over long distances with minimal loss. This principle is fundamental to the operation of modern communication networks.