Introduction to Refraction

The video explains refraction, a phenomenon where light changes direction and speed when passing through different media. It describes how this causes illusions, like the straw appearing broken in water. The video covers phase velocity, the index of refraction, and how density affects light bending. It also explains how different colors of light refract at different angles, leading to a spectrum when passing through a prism.

What causes the illusion of straws appearing detached in water?

• Absorption of light by water

• Refraction of light at the water-air boundary

• Reflection of light at the water surface

• Diffusion of light in water

What remains unchanged when light refracts through different media?

• Phase velocity

• Wave speed

• Frequency

• Wavelength

How is the index of refraction defined?

• Wavelength of light in a vacuum divided by wavelength in a medium

• Frequency of light in a medium divided by frequency in a vacuum

• Speed of light in a medium divided by speed of light in a vacuum

• Speed of light in a vacuum divided by speed of light in a medium

What happens to light when it moves from a denser to a less dense medium?

• It slows down

• It bends towards the normal

• It travels in a straight line

• It bends away from the normal

Why does red light bend less than violet light when passing through a prism?

• Red light has a shorter wavelength

• Violet light travels faster

• Red light has a longer wavelength

• Violet light is absorbed more