Which term is a measure of the change in the speed and angle of light as it passes from one material to another?

Which term is a measure of the change in the speed and angle of light as it passes from one material to another?

• A. Proportions
• B. Relief
• C. Refractive index (RI)
• D. Recovery

Answer: (C)

When light passes from one material to another, its speed changes due to the material’s optical density, and the light’s path bends. The measure that captures both how much the speed changes and how much the direction changes is the refractive index. It’s the ratio of the speed of light in a vacuum to the speed of light in the material, and it governs bending through Snell’s law (n1 sin θ1 = n2 sin θ2). A higher refractive index means light slows more and bends more when entering the material, while leaving a medium with a higher index can bend away from the normal. The other terms don’t describe this optical behavior: proportions is just a general ratio, relief relates to texture or relief on a surface, and recovery has no relation to light’s passage.

When light passes from one material to another, its speed changes due to the material’s optical density, and the light’s path bends. The measure that captures both how much the speed changes and how much the direction changes is the refractive index. It’s the ratio of the speed of light in a vacuum to the speed of light in the material, and it governs bending through Snell’s law (n1 sin θ1 = n2 sin θ2). A higher refractive index means light slows more and bends more when entering the material, while leaving a medium with a higher index can bend away from the normal. The other terms don’t describe this optical behavior: proportions is just a general ratio, relief relates to texture or relief on a surface, and recovery has no relation to light’s passage.