Question 1: Refraction is the bending of light as it passes from one medium to another of different optical density. This change in direction occurs because light changes speed when it enters a new medium.

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

Question 1: What is the refractive index of a medium, and how does it affect the bending of light?

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

Question 2: Explain why a straw appears bent when placed in a glass of water.

Answer: Because light bends when passing from water to air, making the straw appear bent at the water surface.

Question 1: A light ray passes from air into glass with a refractive index of 1.5. What is the speed of light in the glass?

Answer: v = c / n = (3 x 10^8 m/s) / 1.5 = 2 x 10^8 m/s

Question 2: If the speed of light in water is approximately 2.25 x 10^8 m/s, what is the refractive index of water?

Answer: n = c / v = (3 x 10^8 m/s) / (2.25 x 10^8 m/s) ≈ 1.33

Question 1: Describe a simple experiment to observe refraction of light using a glass of water and a pencil or straw.

Answer: Place a pencil or straw partly submerged in a glass of water. Observe from the side; the pencil appears bent at the water surface due to light bending. Variables include the angle of viewing, the depth of the submerged object, and the medium's optical density. Safety precautions include handling glassware carefully to avoid breakage and ensuring the water container is stable.

Question 1: In an experiment, light passes from air into a liquid, and the refractive index is measured to be 1.45. If the speed of light in the liquid is 2.07 x 10^8 m/s, verify the refractive index calculation.

Answer: n = c / v = (3 x 10^8 m/s) / (2.07 x 10^8 m/s) ≈ 1.45, which confirms the measurement.

Question 1: Describe how refraction is utilized in the design of lenses for glasses or cameras.

Answer: Lenses bend light through refraction to focus or diverge light rays, correcting vision or capturing clear images.

Question 2: Multiple Choice: Which of the following best explains why a fish appears closer when viewed from above the water?

Answer: B) Refraction of light at the water surface