Mod 15/16 Light/Mirrors/Lenses/etc. Study Guide

What are the primary subtractive colors?

Magenta, Cyan, Yellow

What are the primary additive colors?

Red, Green, Blue

What color does a red light and a blue light make?

Magenta

Describe the images formed by a concave mirror when the object is placed beyond the center of curvature.

Real, inverted, smaller.

Describe the images formed by a concave mirror when the object is placed at the center of curvature.

Real, inverted, same size.

Describe the images formed by a concave mirror when the object is placed between the center of curvature and the focal point.

Real, inverted, bigger.

Describe the images formed by a concave mirror when the object is placed at the focal point.

None.

Describe the images formed by a concave mirror when the object is placed between the focal point and the mirror.

Virtual, upright, bigger.

How are the focal point and the center of curvature related in a spherical mirror?

The focal point is half of the center of curvature.

How far away does the image in a flat mirror appear to be from the reflected object?

2x as far away as the object is from the mirror.

What kind of images do flat mirrors make?

Virtual, upright, same size.

How are the angles of incidence and refraction related?

Equal.

What is the difference between specular and diffuse reflection?

Specular: parallel rays being reflected and an image being formed; Diffuse: rays come off in random directions and no image is formed.

What happens to light intensity as you double your distance from the light source?

Intensity decreases by a factor of four.

Why can you determine the frequency of any form of electromagnetic wave if you know the wavelength?

Because electromagnetic waves travel at c = 3 x 10^8 m/s.

How do the speeds of different forms of electromagnetic radiation compare?

All the same speed (c = 3 x 10^8 m/s).

What region of the electromagnetic spectrum do we use when we see things?

Visible light.

What region of the electromagnetic spectrum is used for television transmissions?

Radio wave.

How is a rainbow formed?

Through the interaction of sunlight and water droplets via refraction, reflection, and dispersion.

How does atmospheric refraction affect sunrise and sunset?

It causes us to see the sun before it actually comes over the horizon.

How do mirages form?

When light is refracted up due to warmer air.

What is the critical angle?

The angle of incidence that results in total internal reflection.

How do the focal lengths of converging and diverging lenses differ?

Converging lenses have positive focal lengths; diverging lenses have negative focal lengths.

What sign does a virtual image have and where does it form?

A virtual image has a negative sign for distance and is formed on the same side of the lens as the object.

What sign does a real image have and where does it form?

A real image has a positive image distance and forms on the opposite side of the lens as the object.

What kinds of images can a converging lens form?

Both real and virtual images.

What kinds of images can a diverging lens form?

Virtual, upright, and smaller images.

What do light rays have to do to form a real image?

They must converge after passing through the lens or reflecting off the mirror.

When does light refract toward the normal?

When it passes into a more optically dense medium.

When does light refract away from the normal?

When it travels from a more optically dense medium to a less optically dense one.

How is light speed affected when it passes from one medium to another?

Its speed changes depending on the properties of the two media.

When does light NOT refract?

When one substance isn’t transparent, if the angle from normal is 0, or both substances have the same index of refraction.

What is refraction?

The bending of light through a medium.