Astrophysics Flashcards
What is the principal axis ?
The horizontal axis which passes through the centre of the optical lens perpendicular to the lens axis
What is the principal focus ?
Single point were parallel incident rays converge (same distance on either side of the lens )
What is the focal length ?
The distance between the optical centre and the focal point
What is the focal plane ?
The plane perpendicular to the principal axis that contains the principal focus
What is the axial rays ?
Rasa which are parallel to the principal axis. These rays always converge on the principal focus
What type of rays converge on the principal axis ?
Axial rays
What rays converge along the focal plane ?
Non axial rays
What is a lens ?
A transparent piece of glass or plastic with a curved surface to refract light
What is a convex lens ?
Lens that is narrow on the edges and the widest in the centre
I hate is a concave lens ?
A lens where the thickest part is the edges and the narrowest at its centre
What are the steps to draw a convex ray diagram ?
1- parallel to the axis refracts through f ( principal focus )
2- through f refracts parallel to the axis
3- through the centre remains affected
How can calculate magnification ?
Magnification = image height / object height
What is an upright image ?
When the image is the same way up as the object
What is an inverted image ?
If an image is upside down in comparison to the object
What is a real image ?
Rays which intersect on the opposite side of the lens
What is a virtual image ?
When the rays appear to come from a point of intersection on the same side of the lens
What type of object is produced for a concave lens ?
Virtual / upright /diminished
What is the image produce when the object is beyond two focal lengths?
Real / diminished / inverted
I had is the image produced at 2f ?
Real / inverted / equal in size to the object
What is the image produced when the object is between 2f and f ?
Real / inverted / magnified
What is the image produced when the object is between the lens and the primary focus ?
Virtual / magnified / upright
