Understanding Light: Reflection, Refraction, and Lenses

Lens

What is a real image?

An image where real rays intersect

What is a virtual image?

An image that appears to be coming from behind the mirror

Describe the law of reflection as a relationship between the angle of incidence, the angle of reflection, and the normal.

The angle of incidence, angle of reflection and normal all lie in the same plane

Describe the kinds of images that can be formed by plane mirrors.

Only virtual images, little distortion

What type of mirror produces only diverging rays?

Convex

What type of mirror can produce both converging and diverging rays?

Concave

Describe what kind of mirror you would use if you needed to view a large, spread-out area in a small mirror.

Convex

Compare the shapes of convex and concave mirrors. How are they similar, and how do they differ?

Both curved

What kind of images do convex mirrors form?

Opposite, upright, smaller, virtual

What are three uses for convex mirrors?

Side mirrors in cars, store security, parking lots or parkades

A lighted object is placed at the focal point of a concave mirror. Describe the light rays reflecting off the mirror.

Light rays hit the mirror and reflect parallel

Describe how the positions of a mirror, incident ray, reflected ray, and normal are related.

Angle of incidence = angle of reflection, normal is always perpendicular

How does your image in a mirror compare with looking directly at yourself?

Lateral inversion (right is left, left is right)

Describe how light changes its direction when moving from one medium to another.

More dense to less dense: light bends away from normal
Less dense to more dense: light bends towards normal

What property of a medium is given by its index of refraction?

Density

Through which medium does light pass more quickly, one with a refractive index of 1.1 or one with a refractive index of 2.2?

Quicker through refractive index n =1.1

What type of lens produces a real image?

Converging in most cases

What type of lens produces a virtual image?

Diverging always, converging when do

What is one use for a diverging lens?

Telescopes

How is the focal point of a mirror different from the vertex?

F is where parallel light rays will converge
V is the centre point of a mirror

What is the definition of refraction?

Bending of light as it passes at an angle through a different media

Which substance refracts light more, water or glass? Explain why.

Glass, has a higher refractive index (n)

What is the speed of light?

How fast light travels through a medium (299792.458 km/s)

What is the definition of index of refraction?

The ratio of speed of light in a vacuum to the speed of light in a given medium

Resources of light

Incandescence:

Light emitted due to an object heating up (old fashioned light bulbs)

Bioluminescence:

Living creatures that produce light (fireflies)

Chemiluminescence:

Chemical reaction that produces light (glow stick)

Phosphorescence:

Prolonged emission of light following exposure to UV light (glow in the dark t-shirts)

Fluorescence:

Light produced during the exposure to UV light (compact fluorescent lightbulbs)