Understanding Light: Reflection and Refraction Quiz

What happens to light when it hits a mirror?

• It gets absorbed.

• It bends.

• It bounces back.

• It disappears.

Answer explanation

When light hits a mirror, it does not get absorbed or disappear; instead, it bounces back. This reflection is what allows us to see our image in the mirror.

Rohin was observing a straw in a glass of water and noticed that it appeared bent at the surface of the water. What term describes this bending of light as it passes through different materials?

• Reflection

• Refraction

• Absorption

• Transmission

Answer explanation

The bending of light as it passes from air into water is called refraction. This phenomenon occurs because light travels at different speeds in different materials, causing the straw to appear bent at the water's surface.

Which of the following best describes reflection?

• Light passing through a lens

• Light bouncing off a surface

• Light being absorbed by an object

• Light spreading out

Answer explanation

Reflection is best described as light bouncing off a surface. This occurs when light hits a reflective surface, changing direction without being absorbed or passing through.

What is the focal point in optics?

• The point where light diverges

• The point where light converges

• The point where light is absorbed

• The point where light reflects

Answer explanation

The focal point in optics is where light converges, meaning it is the point at which rays of light meet after passing through a lens or reflecting off a mirror. This is crucial for focusing images.

What happens to light when it passes through a convex lens?

• It spreads out.

• It converges to a point.

• It reflects back.

• It disappears.

Answer explanation

When light passes through a convex lens, it bends inward due to refraction, causing the light rays to converge to a point. This is why the correct answer is 'It converges to a point'.

What is the main function of a magnifying glass?

• To absorb light

• To reflect light

• To bend light

• To block light

Answer explanation

The main function of a magnifying glass is to bend light. It uses a convex lens to focus light rays, making objects appear larger and clearer to the viewer.

How does a periscope use mirrors?

• To absorb light

• To reflect light at angles

• To refract light

• To transmit light

Answer explanation

A periscope uses mirrors to reflect light at angles, allowing the viewer to see objects that are not in their direct line of sight. This is essential for its function, making 'to reflect light at angles' the correct choice.

What is the difference between concave and convex lenses?

• Concave lenses make things look bigger; convex lenses make things look smaller.

• Concave lenses make things look smaller; convex lenses make things look bigger.

• Both types of lenses are the same.

• Concave lenses reflect light; convex lenses absorb light.

Answer explanation

Concave lenses diverge light rays, making objects appear smaller, while convex lenses converge light rays, making objects appear larger. Thus, the correct choice is that concave lenses make things look smaller and convex lenses make things look bigger.

What is internal reflection?

• Light reflecting off the surface of water

• Light bouncing within a medium

• Light being absorbed by a material

• Light passing through a transparent object

Answer explanation

Internal reflection occurs when light bounces within a medium, such as in optical fibers. This is different from light reflecting off surfaces, being absorbed, or passing through transparent objects.

Why do we see our reflection in a mirror?

• Because the mirror absorbs light

• Because light bounces off the mirror and into our eyes

• Because the mirror emits light

• Because light passes through the mirror

Answer explanation

We see our reflection in a mirror because light bounces off the mirror's surface and travels into our eyes, allowing us to perceive the image. The other options are incorrect as mirrors do not absorb, emit, or allow light to pass through.