Light Behavior and Lens Functionality

The video explains the concept of refraction, illustrating how light behaves differently in various materials, causing objects like a pencil in water to appear bent. It uses the analogy of a car slowing down on sand to describe how light changes direction when entering different mediums. The video demonstrates refraction with a rear box experiment and explains the importance of angles and normals in understanding light behavior. Finally, it discusses how lenses use refraction to focus light, enabling clear vision.

What happens to light waves when they move from air to water?

• They slow down.

• They disappear.

• They remain unchanged.

• They speed up.

In the car and sand analogy, what causes the car to change direction?

• The car's weight.

• The difference in speed of the wheels.

• The car's engine power.

• The color of the sand.

What is the term for the imaginary line at a right angle to a surface?

• Normal line

• Refracted line

• Parallel line

• Incident line

How does the angle of incidence compare to the angle of refraction when light enters a denser medium?

• They are unrelated.

• They are equal.

• The angle of incidence is larger.

• The angle of refraction is larger.

Why does a pencil appear bent when partially submerged in water?

• Because the pencil is actually bent.

• Due to the reflection of light on the water surface.

• Because water distorts the pencil's shape.

• Due to the refraction of light as it exits the water.

What assumption does the brain make about light that affects how we perceive objects?

• Light is absorbed by objects.

• Light changes color.

• Light travels in straight lines.

• Light travels in curved lines.

What is the focal point in the context of lenses?

• The point where light rays diverge.

• The point where light rays converge.

• The point where light rays are absorbed.

• The point where light rays are reflected.

What type of lens is found in the human eye?

• Cylindrical lens

• Concave lens

• Flat lens

• Convex lens

How do convex lenses affect light rays?

• They absorb light rays.

• They cause light rays to diverge.

• They reflect light rays.

• They cause light rays to converge.

What is the primary function of a lens in the human eye?

• To reflect light away from the retina.

• To focus light onto the retina.

• To change the color of light.

• To absorb excess light.