Question 1: Define refraction in the context of light waves.

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 how the change in speed of light causes refraction when passing from air into glass.

Answer: When light enters a denser medium like glass, its speed decreases, causing it to bend towards the normal line at the boundary between the two media.

Question 3: What is the normal line in the context of refraction?

Answer: The normal line is an imaginary line perpendicular to the surface at the point of contact where refraction occurs.

Question 1: A light ray passes from air into a glass block. The angle of incidence in air is 30°, and the angle of refraction in glass is 20°. Calculate the refractive index of glass using the formula: n = sin(i) / sin(r).

Answer: The refractive index of glass is approximately 1.5.

Question 1: Describe an experiment to measure the refractive index of a transparent material such as acrylic using a ray of light. Include the key variables to control and measure.

Answer: The experiment involves directing a narrow beam of light at a known incident angle onto the acrylic block and measuring the angle of refraction. Variables include the incident angle, the medium's thickness, and the wavelength of light. Safety precautions include wearing eye protection and ensuring the apparatus is stable to prevent accidental movement.

Question 1: A student measures the angles of incidence and refraction when light passes from water into air. The data recorded are: - Angle of incidence in water: 45° - Angle of refraction in air: 30° Calculate the refractive index of water based on this data.

Answer: The refractive index of water is approximately 1.33.

Question 1: Explain why objects submerged in water appear larger or distorted from above the surface. Include the role of refraction in your answer.

Answer: Objects submerged in water appear larger or distorted because light rays bend when passing from water to air due to refraction. This bending causes the object’s image to appear shifted and magnified from the perspective of an observer above the water surface, creating visual distortions.

Question 1: Identify two everyday devices or applications that utilise the principle of refraction and briefly describe how they work.

Answer: Lenses in glasses and cameras use refraction to focus light and correct vision or produce clear images. The prism in binoculars bends light to change the direction of the image, aiding in viewing distant objects.