chapter 11 review mirrors & lenses. what is an angle of incidence? 2 the angle between an...
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Chapter 11 Review
Mirrors & Lenses
What is an angle of incidence?
22
The angle between an incident ray and the normal of an optical device.
Category: Reflection
What is the difference in shape between a convex and a concave lens?
33
A convex lens is thicker whereas a concave lens is thinner in the middle than at the outside edges.
Category: Lenses
What is an optical device? Give three examples.
An optical device is a device that produces an image of an object. Examples: camera, LCD projector, overhead projector, magnifying glass, glasses, eyes, telescopes, microscopes, movie projectors, etc.
Category: Images
What is the principal axis of a curved mirror?
55
A line through the centre of the mirror that includes the focal point (principal focus).
Category: Mirrors
Describe the size, attitude, location, and type of image you get in a plane mirror
66
The image is the same size as the object, upright, behind the mirror, and is virtual.
Category: Mirrors
What is a virtual image?image?
77
An image that cannot be placed on a screen and can only be seen by looking at or through an optical device (light rays diverge from the optical device).
Category: Images
Why does an image appear behind a plane mirror?
88
Rays reflecting off a plane mirror diverge. It you extend these reflected rays back, they would converge behind the mirror.
Category: Mirrors
If an incident ray is at an angle of 20 degrees from the surface of a mirror (not from the normal), what will be the angle of reflection?
99
If the incident ray is at an angle of 20 degrees from the mirror, then the angle of incidence is 90 – 20 = 70 degrees, so the angle of reflection is also 70 degrees.
Category: Reflection
In what situation would a light ray passing through a lens not refract at all?
1010
When a light ray hits a lens at 90 degrees (along it’s normal or principal axis), it will not refract.
Category: Lenses
Describe the size, attitude, location, and type of image obtained by holding an object very far beyond the focal point of a concave mirror.
1111
The image is smaller than the object, inverted, in front of the mirror, and real.
Category: Mirrors
What type of mirror is a cosmetic What type of mirror is a cosmetic mirror and why does a person mirror and why does a person have to be close to it for it to be have to be close to it for it to be useful?useful?Concave. The person must be within the focal point in order to get a larger (magnified) image.
Category: Mirrors
How is a convex lens similar to a concave mirror?
1313
Category: Lenses
They both cause light rays to converge at a focal point. They also form similar images in terms of size, attitude, and type depending on how far away the object is from the lens or mirror.
Give two examples of ways to diffuse light in a room so that it is easier on the eyes.
1414
Using frosted light bulbs, irregular surfaces on ceilings (such as stucco), using lampshades, avoiding too many mirrors or direct light sources.
Category: Reflection
Describe the size, attitude, location, and type of image obtained by holding an object just beyond the focal point of a concave mirror.
1515
The image is larger than the object, inverted, in front of the mirror, and real.
Category: Mirrors
What is diffuse reflection?
1616
The reflection of light off an irregular surface so that it scatters in many directions and an image is not formed.
Category: Reflection
Does a light ray speed up or slow down as it passes from air to water? Does it bend away from or towards the normal?
1717
The light ray slows down and bends towards the normal.
Category: Refraction
Why does the passenger side-view mirror of a car read “Objects in mirror are closer than they appear”?
1818
A side-view mirror is a convex mirror, used because it gives a wide side view. The image in a convex mirror is always smaller, giving the illusion that an object is farther away than it really is.
Category: Mirrors
How would you describe the reflected rays from a convex mirror?
1919
Category: Mirrors
Diverging (they spread apart).
What is a real image?
2020
An image that can be placed on a screen at that can be seen without looking at or through an optical device (light rays converge from the optical device).
Category: Images
How would you describe the reflected rays from a concave mirror?
2121
Converging (they come together).
Category: Mirrors
What is specular reflection?
2222
The reflection of light off a smooth, shiny (regular) surface so that an image is formed.
Category: Reflection
What is refraction?
2323
Category: Refraction
The bending of light as it passes from one material to another (due to a change in speed).
What type of mirror is used in a flashlight and why?
2424
A concave mirror is used because it reflects the light rays from the bulb into a concentrated, parallel beam.
Category: Mirrors
In what situation would a concave mirror produce an upright, virtual image?
2525
When the object is within the focal point of the mirror (i.e. it is very close to the mirror).
Category: Mirrors
What is a lens?
2626
A curved, transparent device that causes light to refract as it passes through. It produces an image of an object.
Category: Lenses
What is the difference between an incident ray and a reflected ray?
2727
An incident ray is a ray of light that travels towards a reflecting surface, whereas a reflected ray bounces off a reflecting surface.
Category: Reflection
What type of mirror is a surveillance mirror? Why?
2828
It is a convex mirror because it reflects light rays from all parts of a room towards a person’s eyes, thus giving a wide view.
Category: Mirrors
Describe the size, attitude, location, and type of image obtained by holding an object in front of a convex mirror.
2929
The image is smaller, upright, behind the mirror, and virtual.
Category: Mirrors
How would you describe light rays passing through a convex lens?
3030
They converge (come together).
Category: Lenses
Describe why the straw appears bent in the glass of water.
3131
The light rays coming from the part of the straw that is under water change speed and direction as they pass from water to air towards your eyes. This makes them appear to come from a place under the water where the straw actually isn’t, so the straw appears bent.
Category: Refraction
What is the difference in shape between a concave and a convex mirror?
3232
A concave mirror is one that curves inwards (the reflecting surface is on the inside curve). A convex mirror curves outwards (the reflecting surface is on the outside curve).
Category: Mirrors
Describe the size, attitude, and type of image produced by a concave lens.
3333
The image is smaller, upright, and virtual.
Category: Lenses
Give two examples of specular reflection.
3434
Light reflecting off a mirror, shiny metal, the surface of still water, etc.
Category: Reflection
What type of lens does a magnifying glass use? Why must you hold the object you are observing close to the lens?
3535
Convex lens. You must have the object within the focal point in order for its image to be enlarged (magnified).
Category: Lenses
Name three devices that use lenses.
3636
Category: Lenses
Camera, LCD projector, glasses, contacts, magnifying glass, microscope, eyes, etc.
Describe the size, attitude, location, and type of image obtained by holding an object within the focal point of a concave mirror.
3737
The image is larger, upright, behind the mirror, and virtual.
Category: Mirrors
What is the focal length of a curved mirror?
3838
The horizontal distance between the focal point and the middle of the mirror.
Category: Mirrors
What happens to parallel light rays that strike a concave lens?
3939
They diverge (spread apart).
Category: Lenses
What is the focal point of a concave mirror?
4040
The point at which all incident parallel light rays are reflected through (where they converge after being reflected).
Category: Mirrors
What are the two laws of reflection?
4141
1. The angle of incidence equals the angle of reflection.
2. The incident ray, normal, and reflected ray all lie in the same plane.
Category: Reflection