Optics Refraction Foundations Quiz

Refraction happens because light travels at different speeds in different media. The key idea is speed change at a boundary, which makes the ray change direction.

Air and water have different refractive indices. The concept is refractive index, which tells you the light’s speed changes and refraction can occur.

Angles are measured from the normal. The concept is the normal line, which is the reference for defining incidence and refraction angles.

By definition, angles are measured from the normal. The concept is angle of incidence, defined relative to the normal line.

At 0° incidence, there is no bending. The concept is normal incidence, where direction stays the same even though speed may change.

Higher refractive index → lower speed → bending toward normal. The concept is refraction toward the normal when entering a higher refractive index medium.

When light travels from a less dense medium to a denser medium, it slows down, causing it to bend toward the normal line. This change in speed results in a decrease in the refracted angle compared to the incident angle. Consequently, the angle of refraction is always smaller than the angle of incidence when light enters a denser medium, illustrating the principles of Snell's law and the behavior of light during refraction.

Rays change direction at the air–water boundary. The concept is refraction at an interface, which shifts the apparent position of the submerged part.

Any wave that changes speed between regions can refract. The concept is wave refraction, which applies whenever wave speed changes across regions.

Refraction shifts the apparent position of the bottom. The concept is apparent depth caused by refraction at the water–air boundary.

Lower refractive index in air → higher speed → away from normal. The concept is refraction away from the normal when entering a lower refractive index medium.

It bends toward or away depending on whether it slows down or speeds up. The concept is direction of refraction, determined by whether the light enters a higher or lower refractive index medium.

A, C, D are refraction; echo is reflection of sound. The concepts are refraction at a boundary (A, D) and dispersion (C), which is refraction depending on colour.

Speed changes cause bending. The concept is speed of light in a medium, which differs between materials and leads to refraction.

Energy is conserved; only direction (and speed in medium) changes. The concept is conservation of energy, meaning refraction redirects light without creating energy.

Higher refractive index generally means more bending. The concept is refractive index, which measures how much light slows in a material and thus how much it refracts.

Refractive index (n) measures how much light slows down in a medium compared to its speed in a vacuum. In this formula, 'c' represents the speed of light in a vacuum, while 'v' is the speed of light in the material. Therefore, the refractive index is the ratio of the speed of light in a vacuum to the speed of light in the material, indicating how much the light bends when entering the medium. A higher refractive index means light travels slower in that material.

v=c/n. The concept is the refractive index relationship, which shows higher n means lower speed.

Most materials have n>1, so v<c. The concept is refractive index greater than 1, implying light slows compared to vacuum.

That’s the core idea. The concept is refraction due to speed change, which explains bending at boundaries.