Light And Optics Flashcards
What is an optical device?
An optical device it is any technology that uses light.
Example: Mirror.
What is a microscope?
A microscope allows you to see great detail by combining the power of at least two lenses.
Example: Compound Light Microscope, Micronisms.
What is a telescope?
A telescope is an optical device for viewing distant objects. There are two types of telescopes called reflecting and reflecting telescopes.
Example: You use a telescope to look at stars.
What is a refracting telescope?
A refracting telescope and has two lenses, one on each end of a long tube. The larger lens is the objective lens that gathers light and focusses the rays towards the eyepiece, which magnifies the object.
Example: Used in spy glasses.
What is a reflecting telescope?
A reflecting telescope uses a circular mirror that curves inward. The curved surface gathers a lot of light. There is another mirror inside the telescope that directs late to the eyepiece.
Example: Used to look at the moon.
What are binoculars?
A binocular is two refracting telescopes put together. They aren’t as powerful as a telescope but they are easier to carry around and use in everyday life.
Example: Used for sightseeing, birdwatching.
What is the ray diagram?
Scientists use ray diagrams to show how light travels. It is a diagram that is used to represent how light travels. Each Ray has an arrow that shows the direction to travel. Ray diagrams can also explain/show the light brightness or intensity of the light changes with distance (gets dimmer the further away you are). Ray diagrams can also explain shadows.
Example: The diagram looks like a lightbulb that has arrows coming out from every direction.
What does it mean for something to be transparent?
An object that light can travel or shine through.
Example: A glass of orange juice.
What does it mean for something to be translucent?
And object that allows SOME light to travel or shine through.
Example: A frosted window.
What does it mean for something to be opaque?
When an object is opaque, it means that no light passes through.
Example: Brick or wood.
What does it mean for something to be non-luminous?
Non-luminous objects are opaque. They don’t produce light.
Example: A pencil.
What does it mean for something to be luminous?
A luminous object is a light source. Something that produces light. Light source will hit opaque objects that surround us and that is why we can see the things that surround us!
What is a regular reflection?
A regular reflection occurs when light rays hit a smooth surface. The rays travel parallel to one another. When the light rays hit the smooth surface, they bounce off the smooth surface and travel in the same direction, travelling parallel. Regular reflection creates a very clear image but your eyes must be in the direct path of that reflected rays to see the reflected image.
What is a diffuse reflection?
Diffuse reflection occurs when a light rain hits a rough or uneven surface. The rays that hit the surface are reflected at different angles. The rays aren’t parallel. Because the rays fans off in different directions the light is scattered and you can see the image from any different location/positions.
What are incident rays?
Incident rays are incoming race, meaning these are the rays that come in to hit the object. (Reflected rays are rays that bounce off the object.)
What are plane mirrors?
Plane mirrors are flat mirrors that provide the clearest reflection.
Example: Bathroom mirrors.
What is the normal?
The normal is the perpendicular line from the mirror at the point of the reflection.
Example: The middle line.
What is the angle of incidence?
The angle of incidence is the angle between the incident rate in the normal.
What is the angle of reflection?
The angle of reflection is the angle between the reflected ray and the normal.
What is the law of reflection?
The law of reflection is the angle of incidence equals the angle of reflection.
Example: If there is a flat surface like your kitchen counter, light bounces off which means the angle of incidence will be the same as the angle of reflection.
What is a focal point?
A focal point is when all raise go to a common point, meaning all rays goes to the same spot.
What is a convex mirror?
A convex mirror’s surface curves outward. They form images that appear much smaller and farther away. Convex mirrors can reflect light from a large area. The focal point is behind the mirror.
Example: Rear-view mirrors.
What is a concave mirror(
A concave mirror’s surface curves inward. The parallel rays all head to a common focal point. Concave mirrors are great at collecting light. The object that is too far away from the focal point appears upside down. An object that gets closer and closer appears larger. An object between the focal point and the mirror appears upright and big.
Example: Telescopes use them.
What is refraction?
Refraction is due to changes in the speed of light. Light travels at about 300, 000km/second but quite often light hits various items and this causes the speed of light to change and causes the angle of light to bend or refract.
Example: A diamond is more dense than water and so a diamond will refract light more than water.
What are lens’?
A lens is a piece of curved glass or other transparent materials. It is smooth and evenly shaped so when light strikes it, the light refracts in a predicable way.
Example: Concave lens and convex lens.
