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Ch 22 test
| Question | Answer |
|---|---|
| a wave that can travel through empty space or matter and consists of changing electric and magnetic feilds | electromagnetic wave |
| do electromagnetic waves require matter? | no |
| an electric feild surrounds every --- object. | charged |
| a magentic feild surrounds every ---. | magnet |
| the transfer of energy as electromagnetic waves | radiation |
| have scientists discovered something that travels faster than light? | no |
| how fast does light travel? | 300,000 km/s |
| what is the major source of energy on earth? | the sun |
| all of the frequencies or wavelengths of electromagnetic radiation | electromagnetic spectrum |
| visible light | light that you can see |
| what is the order of the electromagnetic spectrum? | radio waves microwaves infrared waves visible light ultraviolet light x rays & gamma rays |
| AM= | amplitude modulation |
| FM= | frequency modulation |
| tv stations use --- for sound and --- for pictures. (AM or FM) | FM;AM |
| microwaves are used to send things over --- distances | long |
| what are somethings that involve microwaves? | radar, cell phones, microwaves |
| what does the amount of infrared waves given off depend on? | temperature |
| what is white light? | all of the colors combined |
| longest wavelengths are seen as ---, and shortest wavelengths are seen as ---. | red ; violet |
| what is the range of colors? | the visible spectrum |
| ultaviolet light is produced by the ---. | sun |
| what are some bad effects of ultraviolet light? | sunburn, skin cancer, wrinkles, damage to eyes |
| what are some good effects of ultraviolet light? | kill bacteria on surgical tools, viatmin D |
| can x-rays pass through some materials? | yes |
| gamma rays can be used to treat --- | cancer |
| when light waves bounce off of an object | reflection |
| light reflects off of --- objects | all |
| what is the law of reflection? | states that the angle of incidence is equal to the angle of reflection |
| light beams reflect off all points at the same angle | regular reflection |
| light beams hit and reflect at many different angles | diffuse reflection |
| the transfer of energy carried by light waves to particles of matter | absorption |
| the farther light travels from its source, the --- it becomes | dimmer |
| an interaction of light with matter that causes light to change directions | scattering |
| why is the sky blue? | blue light scatters more than anything else |
| bending of a wave as it passes from medium to another | refraction |
| what are the 2 types of lenses? | convex and concave |
| the bending of waves around barriers or through opening | diffraction |
| a wave interaction that happens when 2 or more waves overlap | interference |
| what are the 2 types of interference? | constructive and destructive |
| the passing of light through matter | transmission |
| what are the 3 types of matter? | transparent, translucent, and opaque |
| light reaches your eyes after being --- or ---. | reflected or transmitted |
| in colored transparent objects, you see --- | the color of the object |
| what are the primary colors of light? | red, blue, and green |
| a material that gives a substance its color by absorbing some colors of light and reflecting others | pigment |
| mixing pigments is called... | color subtraction |
| what are the primary pigments? | yellow, cyan, and magenta |
| light waves travel in all directions from their source in --- lines | straight |
| a ray is the same as --- | an arrow |
| a mirror that has a flat surface | a plane mirror |
| an image through which light does not travel | virtual image |
| a mirror that is curved inward | concave mirror |
| an image through which light passes | real image |
| make a --- to decide image concave forms. | ray diagram |
| a mirror that curves outward | convex mirror |
| a transparent object that forms an image by reflecting light | lens |