Flashcards
p3 - lens
Cards in this deck (13)
- 1Define refractionRefraction is the change of direction of light as it passes from one medium to another.
- 2How does a lens form an imageA lens forms an image by refracting light
- 3What is the refractive index ?the degree to which light refract while passing through a given medium
- 4How do we calculate the refractive indexi is the angle of incidence
r is the angle of refractio
- 5Describe the ray pattern of a converging lens lensIn a convex or converging lens, parallel rays of light are brought to a focus at the principal focus.
- 6What is the focal length ?The distance from the lens to the principal focus is called the focal length.
- 7Describe the ray pattern of a diverging lensA diverging lens makes parallel rays spread out as if they came from a point called the principle focus
- 8How is a real image formed ?A real image is formed by a converging lens if the object is further away than the principle focus
- 9How is a virtual image formed ?A virtual image is formed by a diverging lens and by a converging lens if the object is nearer to the lens than the principle focus . the image is MAGNIFIED
- 10How do you calculate magnification of a virtual image ?image height / object height
- 11describe the image formed when an object is placed between a converging lens and Fthe image formed is virtual , upright , magnified and on the same side of the lens as the object
- 12What is the difference between a real and virtual imageA real image is the image formed where the light rays are focussed. A virtual image is one from which the light rays appear to come but don’t actually come from that image like in a mirror.
You can project a real image onto a screen or wall, A virtual image can not be projected. - 13How does a camera for an imageit contains a converging lens that is used to form a real image of an object. Beyond 2F image is real , diminished and inverted