Flashcards
EM and Astrophysics Definitions HL
Cards in this deck (15)
- 1Define principal axisThe line which joins the centers of curvatures of the lens
- 2Focal pointThe point where all rays paralell to principal axis, passing through the lens, come to focus
- 3Focal lengtDistance between center of lens and focal point
- 4Linear magnificationThe ratio between size of image and size of object
- 5Power of a lens (convex)The extent to which light is bent
p=1/f - 6Dioptresm^-1
- 7Far pointDistance between eye and furthest object wich can be brought into focus.
(Infinity) - 8Near pointDistance between eye and nearest object that can be brought into focus witout strain or aid to the eye.
(25cm) - 9Angular magnificationThe ration between the angle subtended by the object normally and the angle subtended by the object with an optical system
- 10Light yearThe distance traveled by light in one year
- 11Luminosity (of a star)The total ammount of energy (radiated by a star) per secuond (W)
- 12Apparent brightnessThe ammount of energy recieved per unit area per second (Wm^-1
- 13ParsecThe distance when parallax angle subtended is one arc second
- 14Absolute magnitudeThe magnityde as seen from 10pc away
- 15Critical densityThe average density of matter required for the Universe to halt its expansion